Carbon Copy Cloner Overview

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System Requirements

• Mac OS 10.4.8 or higher

Supported configurations

• HFS+ formatted partition or hard drive (excluding volumes used for Time Machine)
• Firewire and USB hard drives including iPods*
• CCC will not backup directly to optical media
• CCC is supported only on machines that officially support Mac OS X Tiger (or higher)

Installing Carbon Copy Cloner

Carbon Copy Cloner is distributed via a disk image -- all documentation and required components are contained within the application on this disk image. You may copy CCC to your Applications or Utilities folder, or anywhere else you prefer.

Working with FileVault home directories

FileVault protects the contents of your home directory by enclosing it in an encrypted disk image. When you log in, the encrypted disk image is unlocked via your login and password and mounted for use as your home directory. Mounted disk images pose an interesting problem to incremental backup utilities. By simply being mounted and accessed (e.g. via browsing the contents), the content of a disk image, and thus the disk image file itself, is modified. If you run CCC while logged in to a FileVault-protected account, there is a strong chance that the FileVault disk image will be modified while it is being backed up, resulting in a corrupted version of the disk image on your backup volume. Also, because the contents of your FileVault-protected home directory are technically on another volume, CCC will not back up the contents of your home directory when backing up your root filesystem (e.g. your boot drive).

For these reasons, you should either exclude your FileVault disk image file from your backup routine while logged into a FileVault-protected account (and set up a separate routine for backing up the contents of your home directory), or you should only run CCC while logged into an account that is not protected by FileVault.

Basic Cloning

In its simplest form, CCC can clone one hard drive to another, copying every single file to create an exact replica of your source hard drive. This is very useful if, for example, your laptop is damaged and you must send it in for repair. Apple recommends that you backup your data before sending it in for repairs because they are not responsible for lost data. With CCC, simply attach an empty firewire hard drive to your laptop and clone your entire internal drive to the firewire hard drive. While your laptop is out for repair, you can boot another system from the firewire hard drive and continue to use your configuration as if booted from your laptop. When your computer returns from repair, simply restore your firewire hard drive back to the laptop's internal drive and you're ready to continue on with life. No data lost, not an icon out of place.

Learn more about performing basic clones with Carbon Copy Cloner

Using CCC for backup and synchronization

CCC can also be used to perform regular backups of your data. When you select a source volume in CCC, you are presented with the contents of that volume (hidden items too). Simply uncheck the items that you do not want to backup, and CCC will provide ample indication what will and will not be copied. Select a target volume to which you would like to backup, then press the clone button. You have the option to delete items on the target that are not on the source, or simply leave them alone. You also have the option to send your files to another Macintosh on your network. CCC will first scan the source and target volumes for the files to be copied, then will copy only the files that have changed. That's a powerful backup!

Learn more about backing up your data with Carbon Copy Cloner
Learn more about backing up your data to another Macintosh on your network

Scheduling tasks for automated backup

The key to a successful backup plan is to actually do the backups regularly. When left to a human, the task often gets tacked on to the end of a very long list of other things to do. When you eventually have a catastrophe, the data is simply gone. You know that feeling -- you just lost six years of family photos. Your kids being born, their first birthdays, their first everything. The answer to this is consistent and regular backups, placed on a schedule and handled automatically by your computer. CCC includes that functionality, and takes it two steps further.

Backups only work when the computer is awake. If you're a mobile user, the scheduled backup task often does not occur (say your laptop is in a briefcase at the time) or it occurs at an inopportune time, consuming hard drive bandwidth that you simply can't afford. CCC solves this problem by allowing you to defer the scheduled task to a time that you know the computer will be on and idle. If the machine is asleep when the task is scheduled to occur, the task will run upon wake. Bad time? Reschedule to any time, any day.

What happens when your scheduled backup starts but your external hard drive doesn't happen to be attached? Usually you just miss that backup attempt and you wind up playing Russian Roulette with your backup. CCC solves this too. If your backup hard drive is unavailable when the task is scheduled to occur (perhaps you're listening to tunes on your iPod at the time), CCC will immediately run the backup when you reattach your hard drive.

Learn more about scheduling backup tasks with Carbon Copy Cloner

Restoring your data from a backup

Carbon Copy Cloner uses tools built-in to the operating system to back up your data and clone your hard drive. Rather than using proprietary archival methods, CCC backs up your data to an ordinary filesystem that you can browse in the Finder or to a standard disk image like those you download over the Internet. Need to restore a file? Simply browse your backup device and copy the file right in the Finder. If you backed up to a disk image, just mount the disk image and locate the file. If you would like to restore an entire volume, the procedure is exactly the same as it was for creating your original backup: use Carbon Copy Cloner. To restore, simply select your backup as the source and the replacement drive as your new target. CCC also creates bootable backups so you also have a "rescue" drive at hand should something happen to your original.

Learn more about restoring specific files from a backup
Learn more about restoring from a clone
Learn more about restoring from a disk image
Learn more about restoring from a backup stored on another Macintosh on your network

What settings are right for me?

Carbon Copy Cloner is packed with many different features. To learn what features and options to use for your particular situation, read through the usage scenarios described in the document titled "Usage Scenarios for Carbon Copy Cloner".

Usage Scenarios for Carbon Copy Cloner

What does CCC cost?

Carbon Copy Cloner doesn't cost you a dime until you completely trust it. That's the way all backup software should work -- pay when you really feel confident that it's going to do the job that it claims. CCC is "uncrippled" shareware, meaning that all features are available whether you've paid or not. No registration is ever required, but once you trust it, a small donation is appreciated for continued development. Choose "Donate to Bombich Software" from CCC's Help menu to send a donation or use the link below. Thanks!

Note: You'll probably notice right away that there is now an ad banner at the bottom of the cloning status panel while CCC is running. I know what you're thinking, it's an abomination! Right? Well, whenever I post updates to CCC, my bandwidth costs go through the roof. Donations aren't keeping up. My options are either to stop delivering CCC or subsidize with ads. I have chosen to subsidize my bandwidth costs with advertising for a company that I know and trust, and can wholeheartedly endorse as a sponsor. I also introduced the ads as unobtrusively as possible -- in a location and at a time that shouldn't affect your use of CCC.

You can make the ads go away by sending in a donation! Simply click on the "I paid" button in the Donation dialog and the ads will no longer appear. If you're affiliated with an Education institution, please click on the "I paid" button *without* sending in a donation (seriously). And while you're waiting for CCC to do its business, feel free to check out Other World Computing's deals on hard drives, RAM, etc. :-)

Donate to Bombich Software

			What to do when you need help with Carbon Copy Cloner

Getting additional help

When you encounter a problem, need clarification, or are unsure what to do, you should consult the online help to see if your question is answered there. In particular, check out the Frequently Asked Questions section. If you don't find what you need in the online help, visit the Bombich Software forums and search for answers there. The forums are our primary avenue of providing support -- they best allow us to provide one-to-many help, build a knowledge base, and identify trends of usage and problems. If you are unable to get the help you need in the forums, or if you have identified a reproducible error condition, submit a problem report via CCC's Help menu. When you submit a problem report, the developers at Bombich Software will attempt to reproduce the problem and find a resolution. If further clarification is required, we will contact you via email.

			What can I do with Carbon Copy Cloner?

[CCC Help] [Browse Help Topics]

I want to clone my entire hard drive to a new hard drive or a new machine
I want to backup my important data or synchronize my backup drive to my boot drive
I want to backup my important data to another computer on my network
I want to backup multiple machines to the same hard drive, each to its own disk image on the drive
I want my backup task to run automatically on a scheduled basis

I want to clone my entire hard drive to a new hard drive or a new machine

There are many different reasons to make an exact clone of your hard drive. Suppose your laptop is damaged and you must send it in for repair. In the meantime, you not only have to borrow another computer for the duration of the repair, you also don't have your data, applications and work environment exactly as they were on your machine. This lack of organization can be very frustrating and inhibit your productivity. When you get your machine back from repair, you have to deal with locating any modified documents on your loaner computer and copying them to your original computer. Also, Apple recommends that you backup your data before sending in a machine for repairs because they are not responsible for lost data.

In this situation, it would be ideal to simply copy off the entire contents of your hard drive to an external hard drive -- to create a "bootable clone" of your production machine. You can then boot a loaner machine from this bootable clone and work from it as if working from your original machine.*

Another common scenario appropriate for cloning is when you have purchased a new computer and you would like to move the entire installation to your new machine. In the past, using CCC for this type of procedure was usually fine. There were and are caveats**, but usually this went quite well. With Apple's transition to the Intel processor, however, it is very common for people to want to migrate from an older PowerPC-based machine to a new Intel-based machine. The version of Mac OS X Tiger that is available for PowerPC machines, however, will not boot the new Intel-based Macintoshes. Therefore, you are encouraged to use the built-in Migration Assistant as prompted when you first boot your new computer. If you are migrating a PowerPC machine to a PowerPC machine, or migrating an Intel-based machine to an Intel-based machine, then, respecting caveats listed below, a basic clone is an ideal way to migrate from one machine to another.

When you need a complete, simple backup of your entire hard drive, use Carbon Copy Cloner's "Backup everything" option.

Learn more about using the "Backup everything" option

I want to backup my important data or synchronize my backup drive to my boot drive

While a complete and bootable clone of your hard drive can be very useful in case of emergencies, it is often desirable to maintain a more frequently updated backup of your most important data in multiple locations. In general, it is wise to always maintain at least three copies of the data that is most important to you: the original, a nearby backup, and an "offsite" backup -- something that is kept outside of your home or office in case something terrible happened where you regularly use your computer. Carbon Copy Cloner 3 has been enhanced to provide additional functionality for facilitating this type of backup plan.

You may also notice that cloning your entire hard drive every time you back up your data takes a lot longer than it should. Why not just copy the items that have changed since the last backup? This functionality is a standard feature of Carbon Copy Cloner 3.

When you want to copy a selection of data from your hard drive, use CCC's "Incremental backup of selected items" option. Likewise, if you want to only copy the items that have changed since a previous backup, use CCC's "Incremental backup of selected items" option.

Learn more about using the "Incremental backup of selected items" option

I want to backup my important data to another Macintosh on my network

Storing your backup on a locally attached hard drive certainly offers speed and space benefits, but if you'd like to store the backups for one or several machines in a central location, or even offsite, then being able to directly backup to another Macintosh on your network is paramount.

Carbon Copy Cloner 3 offers the option of securely copying your selected data to another Macintosh on your network (or anywhere on the Internet for that matter). After a brief setup procedure to establish trust between your machine and the target machine, simply indicate the IP address or hostname of the machine to which you have access and CCC will take care of the rest.

When you want to copy a selection of data from your hard drive to or from a remote Macintosh, use CCC's "Incremental backup of selected items" option, and choose the "Remote Machine..." option from the Target menu. Likewise, if you want to only copy the items that have changed since a previous backup, use CCC's "Incremental backup of selected items" option.

Learn more about backing up your data to another Macintosh over a network

I want to backup multiple machines to the same hard drive, each to its own disk image on the drive

Sometimes backing up your data to a single external hard drive is just too messy and difficult to organize. Suppose, for example, that you have three computers in your household, and everyone backs up to the same firewire hard drive. Where do you put each person's backup? The single hard drive can't maintain multiple operating systems, Mac OS X does not support that. You could split the drive into three partitions, but that isn't very flexible at all. You could clone each person's drive to a folder on the drive, but that's a little difficult to restore from.

A very good solution in a scenario such as this is to use disk images as the medium of your backup. A disk image is a single file residing on your hard drive that contains the entire contents of another hard drive (except for the free space). When you want to access the contents of that filesystem, you double-click on the disk image to mount the disk image as if it were an external drive attached to the machine. Carbon Copy Cloner 3 leverages disk images to provide you the flexibility of storing several complete, bootable*** backups on a single shared external hard drive. (*** Disk images themselves are not bootable, but you can mount them and restore their content to a physical hard drive to produce a bootable, exact replica of the original).

When you want to copy the entire contents or a selection of data from your hard drive to a disk image, select "New disk image..." or "Choose disk image..." from the target menu. If you want to restore a drive from a disk image backup, boot from a drive other than the target, select "Restore from disk image..." from the source menu and locate the disk image. Choose the drive to which you would like to restore from the target menu.

Learn more about backing up to and restoring from disk images

I want my backup task to run automatically on a scheduled basis

It takes a person of strong resolution to manually back up data frequently enough to prevent a catastrophic loss. For the rest of us, there's task scheduling. Carbon Copy Cloner offers hourly, daily, weekly, and monthly scheduling. If your workstyle is too hectic for scheduling, you can also schedule a task to run whenever your backup hard drive is attached to your computer.

To schedule a backup task, first configure CCC as if you were going to run a backup task immediately. Instead of clicking on the Clone button, click on the "Save Task" button. In the Scheduler window that appears, provide a name for the scheduled task and indicate when you want the task to run.

Learn more about scheduling backup tasks with Carbon Copy Cloner

			Using Carbon Copy Cloner to backup selected items on your computer and to synchronize disks

[CCC Help] [Browse Help Topics]

When you want to copy a selection of files to another drive or disk image, you use the "Incremental backup of selected items" option in CCC. This is a really easy way to make a backup of just the files that are important to you, which can be particularly important if your target drive is tight on space. This option also offers a speed advantage -- only the files that have changed will be copied to the target drive. For day to day incremental backups, this is the ideal method for backing up your data and your boot volume.

Configuring what items should be copied (or not)

When you choose a disk in the source menu, and the "Incremental backup of selected items" option is selected, the "Items to be copied" table populates with the contents of that volume. Each file and folder has a checkbox next to it -- unchecking a checkbox indicates that you do not want that item copied to your backup drive. You will also notice that each folder has a disclosure triangle, just like in the Finder. Click on the disclosure triangle to reveal the contents of a folder, then you can continue deselecting items to be copied, if desired. CCC will not allow you to navigate beyond the folders for which you have permission to view. Additionally, if you deselect an item that is required for Mac OS X to boot, CCC will indicate that the target volume will not be bootable. Your target volume will be bootable as long as it meets the bootability requirements and you select to copy all required system files.

Bootability verification

CCC determines whether your target volume will be bootable and indicates this beneath the "Cloning Options" section. To qualify as "bootable", the following requirements must be met:

• The target volume cannot be a disk image -- you cannot boot your Macintosh from a disk image.
• The source and target volumes must be local volumes -- CCC cannot determine the bootability of a remote volume.
• If the Macintosh is a PowerPC Macintosh, the target device must be an internal volume or on a Firewire hard drive. Intel Macintoshes can boot from either an internal volume, a Firewire hard drive, or a USB hard drive.
• The files and folders required by Mac OS X must be present on the source volume. These include: /Library, /System, /Users, /bin, /etc, /mach_kernel, /private, /sbin, /tmp, /usr, and /var.
• The files and folders that are required by Mac OS X must be selected to be copied to the target volume (applicable only to the "Incremental backup of selected items" cloning method).

What is the "Gear" menu for?

The popup menu next to the source menu that has a gear icon is a contextual filters menu. That menu is enabled when you have selected a local volume or disk image in the source menu. In short, filters are created automatically for you when you deselect items in the "Items to be copied" table. You can edit filters and save customized filters for future use, as well as add file type filters and custom rules. Filters are explained in more detail in this section of CCC Help.

Options to the "Incremental backup of selected items" method

By default, the "Incremental backup of selected items" method will copy the selected items to your target drive, copying only the items that have changed and leaving in place any files on the target that do not exist on the source. Essentially, the two drives are merged onto the target. Often when you back up your data, however, you also want to delete items on the backup that have been deleted on your source hard drive. Select the "Delete files that don't exist on the source" option if you would like items that have been deleted on the source to be deleted from the target.

In the event that you accidentally delete a file and don't notice until after your scheduled backup has occurred, you are typically out of luck -- the file is deleted from your backup (when using the "Delete items that don't exist on the source" option). With the "Archive modified and deleted" option, deleted items are not deleted from the backup, rather they are moved to a time-stamped folder at the root level of your backup volume. Should you ever need to recover a long-ago deleted file, or simply the version of a file before last week's major revision, simply navigate to the root level of your backup volume and find the folder named with the date that the backup occurred.

What happens to data already on the target drive?

If you already have data on your target drive, the "Incremental backup of selected items" method will only delete those items if:

1. You have selected the "Delete files that don't exist on the source" option and
2. The file does not exist on the source

If a file exists on the source and target at the same path (e.g. /Users/bob/Desktop/file.txt and /Volumes/Backup/Users/bob/Desktop/file.txt), then the file on the target volume will be overwritten if it is older than the file on the source. Otherwise it will be left untouched.

How do I restore files backed up using the "Incremental backup of selected items" method?

If you need to restore just a file or handful of files, simply browse the backup drive in the Finder and copy those items back to your original drive to restore them. If you need to restore many files using CCC, select the drive that you backed up to as the source, select your original drive as the target, then proceed as you did when you originally backed up your drive. Carefully consider the "Delete files that don't exist on the source" option; if there are other important files on the volume you're restoring to, you don't want to accidentally erase them. Also, you may deselect the root of a volume in the "Items to be copied" table, then re-select only a few items to limit what items are restored. Note that you cannot select the boot drive as the target, you will need to boot from another drive if you need to restore directly to your boot drive.

What else can I do with the "Incremental backup of selected items" method?

In addition to backing up your data or synchronizing one volume to another, CCC also allows you to back up selected files to a disk image and to back up selected files to another computer on your network.

Learn more about backing up to disk image
Learn more about backing up to a subfolder on a hard drive
Learn more about backing up to a remote host

			Using Carbon Copy Cloner to create an exact clone of your hard drive

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Carbon Copy Cloner's most basic and revered task is to create a "carbon copy" bootable clone of a hard drive. CCC 3 takes this to a new level with Apple Software Restore, a low-level tool developed by Apple and built-in to Mac OS X. Apple Software Restore is the most highly regarded tool for performing disk to disk clones, and Carbon Copy Cloner brings all the functionality and more to your desktop. To clone a hard drive using Carbon Copy Cloner, use the "Backup everything" method listed under Cloning options:

The "Backup everything" method will attempt a block-level clone of your source volume if you have indicated to "Delete items from the target that don't exist on the source". If you have not selected that option, or if a block-level clone cannot proceed (see below), this cloning method will perform a file-level copy of everything on the source volume to the target volume. If the target volume already contains some of the content of the source volume (e.g. from a previous backup), that content will be efficiently updated. The end result in both cases is an exact, bootable backup of your source volume.

Options to the "Backup everything" method

This cloning method has one option: Whether to delete items from the target that don't exist on the source prior to cloning. This option is important to consider when your goal is to create a bootable clone -- read the gray box at the bottom to understand how this option affects your clone.

Block-level copies vs. file-level copies

Cloning an entire hard drive to another drive can be achieved in two ways: 1) Copying every file individually from one volume to the other or 2) Copying the underlying blocks from one hard drive to the other. These two methods are called "file-level copying" and "block-level copying", respectively. While each method produces functionally the same result, block-level copies are almost always significantly faster than file-level copies, and are therefore the preferred method for disk to disk clones.

To benefit from a block-level copy, the following criteria must be met:

1. You must choose to "Delete items from the target that don't exist on the source" during the clone.
2. You must be able to unmount both devices (there cannot be any open files on either drive and you cannot be booted from either drive). Do not actually unmount the drives prior to the clone.
3. The target drive must be at least as large as the source drive.

If any of these criteria are not met, CCC will automatically fall back to a file-level clone. A file-level clone will yield the same result -- a bootable clone (assuming you didn't merge two operating systems), but it will take a little longer.

While a block-level clone is rarely required to insure the fidelity of your backup, some people find comfort in the fact that, block-for-block, the resulting target is precisely like the original (this is simply impossible with a file-level clone). When possible, CCC will always prefer a block-level clone. However, don't lose sleep if meeting the requirements for a block-level clone is untenable for your particular backup or cloning situation. The file-level backup engine in CCC has been tuned and honed to bring the best performance and fidelity possible among Mac OS X backup utilities.

Do I need to clone, or just backup?

Often people clone when all they really need is a backup. When you clone a volume, every file is copied, and this can take a fair amount of time. If you just recently backed up your entire drive, use the "Incremental backup of selected items" method to backup your data instead. That method copies only the items that have changed, thus your backup is much faster. If you're moving to a new hard drive, cloning your machine prior to repair, etc. then the cloning method is the right choice for you.

Bootability verification

CCC determines whether your target volume will be bootable and indicates this beneath the "Cloning Options" section. To qualify as "bootable", the following requirements must be met:

• The target volume cannot be a disk image -- you cannot boot your Macintosh from a disk image.
• The source and target volumes must be local volumes -- CCC cannot determine the bootability of a remote volume.
• If the Macintosh is a PowerPC Macintosh, the target device must be an internal volume or on a Firewire hard drive. Intel Macintoshes can boot from either an internal volume, a Firewire hard drive, or a USB hard drive.
• The files and folders required by Mac OS X must be present on the source volume. These include: /Library, /System, /bin, /etc, /mach_kernel, /private, /sbin, /tmp, /usr, and /var.
• The files and folders that are required by Mac OS X must be selected to be copied to the target volume (applicable only to the "Incremental backup of selected items" cloning method).
• If the Macintosh is a PowerPC Macintosh, the hard drive on which the target resides must be partitioned using the Apple Partition Map. Intel-based Macintoshes ship with hard drives formatted with the GPT (GUID Partition Table) format, and will not boot a PowerPC Macintosh.

What else can I do with the "Backup everything" method?

In addition to cloning one volume to another, CCC also allows you to clone a volume to a disk image.

Learn more about cloning to disk image

How do I restore files backed up using the "Backup everything" method?

If you need to restore just a file or handful of files, simply browse the backup drive in the Finder and copy those items back to your original drive to restore them. If you need to restore a larger subset of files, but not the entire volume, click here to learn how to restore files with the "Incremental backup of selected items" option.

To restore an entire volume, for example your boot volume after a disk failure, you will need to boot from an external firewire hard drive. Ideally, you will simply boot from the firewire hard drive that you backed up to using CCC. Launch CCC, select the drive that you backed up to as the source, select your original (or replacement) drive as the target, choose to "Backup everything", then clone. If the target drive must be bootable, you must use the "Delete items from the target that don't exist on the source" option (see below for the explanation).

			Using Carbon Copy Cloner to backup to and restore from disk images

[CCC Help] [Browse Help Topics]

Sometimes backing up your data to a single external hard drive is just too messy and difficult to organize. Suppose, for example, that you have three computers in your household, and everyone backs up to the same firewire hard drive. Where do you put each person's backup? The single hard drive can't maintain multiple operating systems, Mac OS X does not support that. You could split the drive into three partitions, but that isn't very flexible at all. You could clone each person's drive to a folder on the drive, but that's a little difficult to restore from.

A very good solution in a scenario such as this is to use disk images as the medium of your backup. A disk image is a single file residing on your hard drive that contains the entire contents of another hard drive (except for the free space). When you want to access the contents of that filesystem, you double-click on the disk image to mount the disk image as if it were an external drive attached to the machine. Carbon Copy Cloner 3 leverages disk images to provide you the flexibility of storing several complete, bootable* backups on a single shared external hard drive. (* Disk images themselves are not bootable, but you can mount them and restore their content to a physical hard drive to produce a bootable, exact replica of the original).

Backing up to a new disk image

After choosing a source volume from the Source Disk popup menu, choose "New disk image..." from the Target Disk popup menu. Provide a name and choose a location to save your disk image. If you plan to back up to this disk image again in the future, select the option to "Create a read/write sparse disk image". If you want a read-only disk image for archival purposes, choose the option to "Create a read-only disk image". Note that if you schedule a task in which you create a new image, CCC will recreate the image every time the task runs. See the Backing up to an existing (read/write) disk image section below for a more appropriate choice for scheduling backups to a disk image.

Read/write "sparse" disk images
A sparse disk image is a type of read/write disk image that grows as you copy files to it. In general, sparse disk images only consume as much space as the files they contain consume on disk, making this an ideal format for storing backups.

Read-only disk images
When creating a read-only disk image, you have two additional options. If your target disk is short on space, you can compress the disk image. Compression rates vary on the content of your source, but you can typically expect to reduce the size of your disk image by about half when using compression. There is a subtle behavior that you should take note of when considering this option as a space-saving measure: When using the "Incremental backup of selected items" cloning method, CCC will first create a read/write disk image, copy the selected items to it, then convert the disk image to read-only compressed. In this case, you will actually need twice the space on your target as the items to be copied consume on the source. When using the "Backup everything" cloning method, this limitation does not apply, CCC will create a read-only compressed disk image in one step.

The second option allows you to segment the disk image. This option is ideal if, for example, you intend to burn the segments to optical media.* Like with the compression option, CCC will also create a temporary read-write disk image -- not segmented -- when using the "Incremental backup of selected items" cloning method.

* To mount a segmented disk image, all segments must be present on the same media. Burning disk image segments to optical media is a great archival practice, just keep in mind that should you ever need to restore from that backup, you will first need to copy all segments onto a volume with adequate capacity.

Encrypting disk images
If any of the data that you are backing up is sensitive, and if your backup device may be in an insecure location, it is a good idea to enable encryption when backing up to a disk image. CCC uses 128 bit AES encryption to encrypt disk images. Note: CCC does not currently support encryption during scheduled tasks.

Backing up to an existing (read/write) disk image

If you regularly make backups to a disk image, this is the option you will want to choose when choosing a target disk. After choosing a source volume from the Source Disk popup menu, choose "Choose disk image..." from the Target Disk popup menu. In the Open dialog box, navigate to and select your disk image and click the OK button. After clicking on the Clone button, CCC will mount the disk image and backup your data as if it were any other backup device.

When backing up to an existing disk image, be sure to choose a disk image that is writable. If you choose a sparse disk image that CCC created in a previous backup, CCC can be configured to copy everything again, overwriting data on the disk image, or to copy only the items that have changed. A sparse image will grow as data is copied to it.

Learn more about performing basic clones with Carbon Copy Cloner
Learn more about backing up your data with Carbon Copy Cloner

Restoring from a disk image

To restore files or an entire filesystem from a disk image, simply select "Restore from disk image" from the Source Disk popup menu and locate your backup disk image. CCC will mount the disk image and you may then proceed with the restore procedure using either the "Incremental backup of selected items" or "Backup everything" cloning method. If you want to restore your disk image to your boot volume, you will first need to boot from another installation of Mac OS X. Follow these steps before proceeding with the restore procedure defined above:

1. Install Mac OS X and CCC onto an external USB or Firewire hard drive
2. Boot from that external hard drive and launch CCC

			Using Carbon Copy Cloner to backup to another Macintosh on your network

[CCC Help] [Browse Help Topics]

Carbon Copy Cloner 3 offers the option of securely copying your selected data to another Macintosh on your network (or anywhere on the Internet for that matter). After a brief setup procedure to establish trust between your machine and the target machine, simply indicate the IP address or hostname of the machine to which you have access and CCC will take care of the rest.

To successfully set up CCC to back up to a remote Macintosh, you will be required to:

1. Enable Remote Login on the remote Macintosh
2. Determine the Unix path to the folder on that machine that you would like to back up to
3. Install an "Authentication Credentials" package on your local machine (CCC will place this package on your Desktop)
4. Transfer that same "Authentication Credentials" package to your remote Macintosh and install it there
5. Verify that the system time on each Macintosh is reasonably in sync with the other
6. Confirm that the backup device on the remote Macintosh is ready and mounted (CCC does not currently perform this verification).

Configuring CCC to back up to a remote Macintosh is an advanced configuration scenario. If you are unsure of any of these settings, please seek advice at the Bombich Software Forums before proceeding.

Enabling Remote Login on the remote Macintosh

To enable Remote Login on your remote Macintosh, log in to that machine as an admin user and launch System Preferences. Open the Sharing Preference Pane and check the box next to "Remote Login". Take note of the message at the bottom of the window, e.g. "To log in to this computer remotely, type "ssh username@yourhost.yourdomain.com" at a shell command prompt." The text after the "@" symbol is the hostname or IP address that you will provide in CCC's "Remote Macintosh" dialog box.

Determining the "Path to backup directory"

To determine the value to enter in this field, first log in to the remote Macintosh as an admin user and create the destination folder. Click on the destination folder, then from the Finder's "File" menu, choose "Get Info". In the "General" section of the Get Info panel, the "Where" attribute indicates where that folder is located. The path to your backup directory will consist of that location, plus "/", plus the name of your destination directory. For example, I just created a folder named "Mike-Backups" in the Shared directory on my remote Macintosh. The Get Info panel indicates that it is located at "/Users/Shared", therefore the path to my backup directory is "/Users/Shared/Mike-Backups". Note: while spaces and special characters should not pose a problem in the backup directory path, I strongly recommend that you avoid them.

The "Authentication Credentials" package installer

Before you can back up to a remote Macintosh, you must first set up "public key authentication" (PKA) between the Macintosh that you're running Carbon Copy Cloner on and the Macintosh that you'd like to back up to. With PKA, you don't need to provide a username/password to access the remote machine. Instead, CCC uses pre-shared, 128-bit key pairs to identify the source and target machines. When you click on the button to create an Authentication Credentials installer, CCC will generate this key pair and create a package installer. The "Authentication Credentials Installer" installs the key pair into the root account on your machine and then into the root account on the target machine. You must install them in this order. If you already have a public/private key pair in your root account, that is used instead and copied into the Authentication Credentials Installer package.

Note that you are NOT required to enable the root account on either machine. This is avoided by using public key authentication instead of password-based authentication.

Remote machine requirements

At this time, CCC requires the use of the root account (does not have to be enabled) on both the source and target machines. To successfully back up to a remote machine, you must have administrative privileges on both machines. This may be improved upon in a future release.

CCC also requires that the remote machine be running Mac OS 10.4.8 or later. The ability to back up to non-Mac OS X machines may be improved upon in a future release.

CCC does not currently support backing up directly to an AFP, NFS, or SMB network share. You can back up to a disk image on these types of volumes, but a volume to volume clone is not permitted (or technically feasible) to network shares.

Additional pointers for advanced users

Carbon Copy Cloner's public key-based authentication is designed to work with no additional configuration of the services required for backing up over a network connection. CCC uses rsync over an ssh tunnel (port 22 by default) to perform the backup. If you do make modifications to the sshd configuration, consider how that may affect your backup. For example, CCC requires use of the root account over ssh. If you set the "PermitRootLogin" key in the sshd.conf file to "no", you will not be able to use CCC to or from that machine. It's an important distinction to note that the root account does not have to be *enabled*, but sshd must permit the use of the root account.

Restoring from a backup on a remote machine

The restore procedure is nearly identical to the backup procedure. Launch CCC, then select "Remote Macintosh..." from the source menu. In most cases, the Remote Settings dialog will be populated with the same information you used to back up originally. Select a target volume, then click the Clone button. Carefully consider the "Delete files that don't exist on the source" option; if there are other important files on the volume you're restoring to, you don't want to accidentally erase them. Also, when restoring from a remote Macintosh, you will not be given the choice of what files to restore, it's all or nothing. Note that you cannot select the boot drive as the target, you will need to boot from another drive if you need to restore directly to your boot drive.

			Configuring filters in CCC to limit what is backed up

[CCC Help] [Browse Help Topics]

Typically when you clone your hard drive to another drive, you want to copy everything. When you perform regular incremental backups, however, space becomes an issue. Filters allow you to specify what items on your hard drive should not be copied to the backup device when using the "Incremental backup of selected items" cloning method. A filter is created automatically for you when you uncheck items in the "Items to be copied" table. More advanced filtering options are available as well, including the ability to exclude items based on file type and the ability to specify your own rsync-compatible rules.

Creating filters

Creating your own filters is a breeze. Simply choose a source volume in the Source Disk popup menu, then start deselecting items that you do not want to copy. As you deselect items, the default filter for that volume is updated with your selections. To view and edit the filters that you have created, click on the "gear" popup menu next to the Source Disk popup menu. [If this button is disabled, select a source volume from the Source Disk popup menu.]

In the Filter Settings window, you see a list of filters on the left and the contents of those filters on the right. Every time you choose a volume from the Source Disk popup menu, a filter is created for you with a name in the form of "Source Disk (Default)". As you deselect items to be copied, those items are added to the filter. When you quit CCC, the filters are saved and available the next time you launch CCC. Whenever you choose a volume in the Source Disk popup menu in the future, the settings from the default filter for that volume will be applied.

Customizing filters

Typically you will not need to manually configure your filters. If you would like to maintain more than one filter for a particular volume, or if you would like to apply more advanced settings such as file type filters, then you do so in the Filter Settings window. To create a new filter, click the "+" button and provide a name for the filter. To remove a filter, select the filter in the Filters table and click on the "-" button. If you delete a default filter for a volume, that filter will be recreated the next time you select that volume in the Source Disk popup menu.

To delete items from a filter, select the item(s) from the "Items you have excluded..." table on the right and click the "-" button or press the delete key.

Advanced filter options

If the files you want to exclude are scattered across your filesystem, it may be tedious to manually exclude each of them. To address this, CCC implements file type filters. File type filters allow you to specify a file extension (e.g. "dmg", "doc", "mp3", etc.) of a file type that you would like to exclude. Suppose you want to exclude disk images from being backed up, for example*, simply add "dmg" to the File types filter table and any file with that extension will be excluded.

For the truly adventurous, CCC permits the definition of custom rules. These custom rules follow the syntax defined in the rsync man page. Using the rules in the screenshot above as an example:

- Library/Caches
- /var/log
- /Library/Logs

The "No logs or cache" filter will exclude any item that contains "Library/Caches" *anywhere* in the path (for example, ~/Library/Caches in every users home directory as well as in /Library/Caches). Items in the /var/log folder at the root of the volume will be excluded as well as items in /Library/Logs (but not, for example, in /Users/mike/Library/Logs).

You can learn more about custom rules by reading the "EXCLUDE PATTERNS" section of the rsync man page.

Note: Filters specified in the "Advanced options" section of the Filter Settings window will not be reflected in the "Items to be copied" table in the main window.

Suggested additions to your custom filters

As indicated above, read/write disk image files should excluded from an incremental backup regimen unless they are infrequently used. By examining many months of backups, I have discovered that the following "disposable"items also consume too much space on my backup hard drive:

• ~/Library/Caches
• /Library/Logs
• /var/log

Items automatically ignored

When copying files using the "Incremental backup of selected items" cloning method, CCC automatically ignores certain files and folders from the backup procedure. The contents of this list were determined based on Apple recommendations and years of experience. The following is a list of the items that are excluded. This list is not configurable (though the curious would eventually learn that these are defined in Carbon Copy Cloner.app/Contents/Resources/defaults.plist).

• .Spotlight-V100
• /.fseventsd
• /.hotfiles.btree
• /.vol/*
• /Auth.bak
• /Backups.backupdb
• /Cleanup At Startup
• /TheVolumeSettingsFolder
• Trash
• .Trash
• .Trashes
• /TheFindByContentFolder
• /Shutdown Check
• Temporary Items
• /VM Storage
• /OpenFolderListDF
• /Desktop (Mac OS 9)
• /.com.apple.NetBootX
• /Volumes/*
• .VolumeIcon.icns
• /dev/*
• /automount
• /Network
• /private/var/vm/*
• /private/tmp/*

			Scheduling backup tasks in Carbon Copy Cloner

[CCC Help] [Browse Help Topics]

Carbon Copy Cloner offers hourly, daily, weekly, and monthly scheduling. If your workstyle is too hectic for scheduling, you can also schedule a task to run whenever your backup hard drive is attached to your computer. To schedule a backup task, first configure CCC as if you were going to run a backup task immediately. Instead of clicking on the Clone button, click on the "Save Task" button. In the Scheduler window that appears, provide a name for the scheduled task (double-click "Untitled") and indicate when you want the task to run.

Scheduling a task

To schedule a task, choose the desired repetition interval from the popup menu next to "Run this task:". If you would rather have the backup task run only when the target volume is reattached to your computer, choose "When target is reconnected".

Next choose how many (hours, days, weeks, or months) you would like to skip between backup events ("Repeat every:"). Finally, indicate the time of day at which you would like the event to start. When scheduling a task to run on a weekly basis, you may also indicate what days of the week on which your task should run. At the bottom of the scheduler window, CCC will indicate how frequently the task will run and when it is next scheduled to run.

Additional Settings

By default, CCC uses the name and Universally Unique Identifier (UUID) of your source and target to identify those volumes. By verifying both of these identifiers, there is less risk in, for example, backing up to a volume that has the same name as your usual target but is not actually the target. While beneficial, this behavior can sometimes have the wrong result. For example, if you rotate between a pair of firewire hard drives, even though they have the same name (e.g. "Offsite Backup"), CCC will not, by default, backup to both of them, it will claim that the UUID of one of the drives does not match that of the originally chosen target.

The deal with this scenario, CCC allows you to disable verification of the target drive's UUID. When deselecting this option, be vigilant that you do not rename your target hard drive and that you never attach a hard drive to your machine that is named the same as your target hard drive.

In addition to disabling the UUID verification, CCC will also allow you to disable verification of the target volume's name. Obviously, both of these options may not be disabled at the same time (CCC won't let you do that), but in cases where you may want to rename your target hard drive, this option will allow you to do so without breaking your scheduled backup task.

If your target hard drive is an iPod, CCC will provide an additional option in the Settings tab: "Wait for iPod:iTunes sync to complete before copying data". When you bought your iPod, you probably did so with the intention of using it to enjoy your music collection. To this end, Carbon Copy Cloner recognizes that the primary purpose of an iPod is for music, and respects the synchronization period that occurs when you connect your iPod to your Mac. This option is enabled by default.

The Description tab indicates the name that you have provided for your backup task as well as a description of the task. CCC populates this description with the one provided in the main interface, but you may modify this description to suit your needs.

Managing and monitoring scheduled tasks

Scheduled task settings may be modified at any time. You can also temporarily disable a scheduled task by unchecking the box next to its name in the "Scheduled Tasks" list. To delete a task altogether, simply select the task in the "Scheduled Tasks" list and click the "-" button or press the delete key. If the task is running when you save modified settings or delete the task, the scheduled task itself will prompt for verification that you intend to end the running task. Choosing to not end the running task will not prevent the settings from being saved, but it will prevent the settings from taking effect. The new settings will take effect the next time you restart your computer or when you modify another setting and re-save them.

If you would like to run a scheduled task immediately, select the task in the "Scheduled Tasks" list and click on the Run button.

In addition to feedback provided in the interface, CCC records some information about your scheduled task in a log file. While the contents of this log file are generally intended for communication of problems to the developer, end users may find some of the information in this log helpful. CCC's log file is located at /Library/Logs/CCC.log. You can view the contents of this log by selecting "CCC Log" from CCC's Window menu.

Learn more about the CCC log file

Deferring and skipping scheduled tasks

Occasionally, a scheduled task will run at the most inconvenient time. Perhaps you are under deadline and don't have the patience for the hard drive performance hit of a system-wide backup. Or perhaps you are just about to pack up and hit the road. If you ever find the need to cancel a scheduled task at a particular time, CCC gives you two options for maintaining your backup regimen: 1) skip this particular scheduled run time or 2) defer this scheduled task to a specific time in the future.

When you skip a task, CCC will run the backup at the next scheduled interval. Deferring gives you more flexibility. Suppose that all you need are another twenty minutes to finish a project. Click defer and wind the clock forward twenty minutes -- CCC will run the task again then. Or suppose you realize that you forgot to bring your backup drive to work with you today and you have a scheduled task that runs every other hour. Rather than getting reminded of this four times, simply defer the backup to tomorrow.

Additionally, CCC offers you the option of permanently rescheduling a backup task. If, after a week or so, you realize that the originally scheduled time is really just too inconvenient, you can modify the start time in the defer panel by checking the box to "Reschedule all future events for this time of day". For more significant modifications to your backup scheduled, launch CCC and choose "Scheduled Tasks" from the Carbon Copy Cloner menu to edit your task.

What if ...?

What happens if no one is logged in when the scheduled task runs?
The scheduled task will run whether someone is logged in to the machine or not. If no one is logged in to the machine, CCC will run in the background without a user interface. CCC logs information to /Library/Logs/CCC.log, you can use that log file to monitor CCC progress (e.g. logged in remotely via SSH).

How is system sleep handled?
If a backup task is scheduled to run while your computer is sleeping, CCC will run that task immediately upon wake (CCC waits 10 seconds to allow your machine to establish network connectivity and spin up hard drives).

What if the backup drive is not available when the scheduled task runs?
If your backup hard drive is unavailable when the task is scheduled to occur (perhaps you're listening to tunes on your iPod at the time), CCC will report an error that the drive is not available and ask you to skip or defer the task. If you choose to skip the task, CCC will immediately run the backup when you reattach your hard drive. If you do not attach the hard drive to your computer before the next scheduled run time, CCC will prompt you again that the hard drive is missing.

How do scheduled tasks "work"

Carbon Copy Cloner Scheduled tasks are managed by launchd. Each scheduled task exists in the form of a property list file stored in /Library/LaunchDaemons. When these LaunchDaemons are loaded, an instance of "ccc_helper.app" is launched and configured with the scheduled task settings.

			Getting more information about what is happening during the clone

Previous versions of Carbon Copy Cloner included a log that indicated the specific Unix commands that were running "Under the hood". CCC version 3 was completely rewritten and uses new techniques to back up your data. While some of those techniques still leverage the Unix underpinnings of Mac OS X, much of CCC now uses lower level features of the operating system that are not appropriate for logging (for example, you would not be able to "run the commands" in the Terminal application).

Learn more about (manually) creating a bootable backup of Mac OS X

Carbon Copy Cloner version 3 does, however, produce a log of output (/Library/Logs/CCC.log) that is useful primarily to the developer. You can use this log to verify the productivity of your scheduled tasks. To view CCC's log file, choose "CCC Log" from the Window menu. Beta versions of CCC will produce more output than non-beta versions. Additionally, you can manually enable debug logging by running this command in the Terminal:

defaults write com.bombich.ccc debug -bool YES

Debugging output is only useful to the developer, so don't enable debug logging unless instructed to do so for support purposes. CCC imposes a size limit of 1MB on the log file. When this limit is reached, the log is rolled over.

Comment on the "Data copied" figure reported in the CCC.log
This value indicates the data written that was actually consumed as disk space. For example, suppose you copy a single file that occupies a single 4Kb block (4,096 bytes) on the disk, but that file fills only 32 bytes of that block. This value represents the accumulation of those 32 byte values. This value will *not* correspond to the value of disk usage indicated in Disk Utility (not even close in most cases), Disk Utility reports the number of blocks occupied multiplied by the size of the block.

			Configuring Advanced Settings in Carbon Copy Cloner

[CCC Help] [Browse Help Topics]

Carbon Copy Cloner includes a few features that require a little consideration and research before using. These features are accessed by choosing "Advanced Settings..." from the Carbon Copy Cloner menu.

Clone to a subfolder on the target volume

There are two typical scenarios in which you may want to clone the contents of your source volume to a subfolder of the target volume rather than the root level of the target volume: 1) You maintain items at the root level of your target volume that you do not want to be erased, yet you want to do incremental backups, deleting items on the backup that were deleted from the source. 2) You want to use the target volume to back up more than one computer.

In the first scenario, your goal is to make regular, incremental backups to a target volume, deleting from the backup the files that you have deleted from the source. Except you don't want to delete items that were on the target volume before you started backing up! In general, these are conflicting goals. However, previous versions of CCC handled this situation quite gracefully. CCC version 3 uses a different approach to backing up than previous versions, and it is no longer capable of simply excluding preexisting items on the target volume. There are two solutions to this dilemma. The first is to use the "Clone to a subfolder..." setting. By specifying a subfolder (simply indicate the name of a folder, CCC will create it if it does not exist), CCC will copy the contents of your source volume into a single folder on the target volume. Any other files or folders on the target volume will be left unaffected. If you choose to use the "Delete items that don't exist on source", this rule will only apply to items within the subfolder that you have indicated.

While this seems like the perfect solution to the problem, note that you will not be able to boot from the backup volume, nor will you be able to select the subfolder as a source volume. You can still access your backup files via the Finder. An alternative to this method is to place items from the target volume that you don't want to lose into a directory prefixed with "_CCC", then specify the "Archive modified and deleted items" option. When using this option, CCC automatically ignores any directory prefixed with "_CCC", as that is the prefix used on the directories used to store archives of modified and deleted items. Another alternative is to clone to a disk image on the target. This option is explained below.

In the second scenario, your goal is to backup multiple computers. Despite that it is tempting, you are discouraged from using the "Clone to subfolder" feature to solve this problem. Instead, you should clone to separate disk images.

Learn more about backing up to and restoring from disk images

Run a shell script (before or after) the clone operation

If there is functionality that you need that does not exist within CCC, pre and post clone shell scripts may be the solution for you. For example, suppose you want to back up your Open Directory Master with CCC at regular intervals, but you know that a simply file-level copy will not properly back up an open database. The following pre-clone shell script will archive your OD master to a disk image for later restoration via Server Admin. It also dumps copies of Server Admin configurations as well as your MySQL databases:

#!/bin/sh

# Path to recovery directory (permissions should be 700 -- read-only root or admin)
recover="/etc/recover"

# mysqldump the databases
echo "Dumping MySQL databases"
mysqldump --user=root --password='s3kr!t' -A > $recover/mysql.dump

# grab the server configuration plists (only specify services that are enabled,
# use "serveradmin list" for a list of services)
echo "Generating serveradmin configuration plists"
services="afp dhcp dns ipfilter nat network swupdate vpn web"
for service in $services; do
    serveradmin -x settings $service > $recover/serverconfig/$service.plist
    sleep 1
done

# Backup Open Directory (if it's Thursday)
day=`date ''+%u''`
if [ $day != 4 ]; then exit 0; fi

od_backup=$recover/od_backup
ts=`date ''+%F''`
echo "dirserv:backupArchiveParams:archivePassword = s3kr!t" > $od_backup
echo "dirserv:backupArchiveParams:archivePath = $recover/od_$ts" >> $od_backup
echo "dirserv:command = backupArchive" >> $od_backup

serveradmin command < $od_backup

Pre-clone shell scripts run after you authenticate, and before any other tasks (e.g. mounting a target disk image, erasing the target). Post-clone shell scripts run after all other tasks have completed successfully. CCC passes as parameters both the source and target paths. For example, the following shell script:

#!/bin/sh

echo "Running $0"
echo `date`
echo "Source: $1"
echo "Target: $2"

Would produce the following output (typically in /Library/Logs/CCC.log, though you can redirect as desired):

Running /etc/postaction.sh
Wed Aug 14 21:55:28 CDT 2007
Source: /Volumes/Home
Target: /Volumes/Offsite Backup

Output from your pre- and post-clone shell scripts will be logged in /Library/Logs/CCC.log. CCC may drop the last output from your script, however, because output handling is handled asynchronously to avoid impacting performance of the backup task. To force all output to be logged, you can add "sleep 1" at the last line of your script.

Also, if your pre-clone script exits with a non-zero exit status, it will cause CCC to abort the backup operation. This can be used to your advantage if you want to apply preconditions to your backup operation. Alternatively, you can add "exit 0" at the end of your script to prevent any errors in your pre-clone script from aborting the backup task.

			Updating Carbon Copy Cloner

Carbon Copy Cloner version 3 includes a new software update feature. To check for application updates, launch Carbon Copy Cloner and choose "Update CCC..." from the Carbon Copy Cloner menu. By default, CCC will automatically check for updates once a day. To change this preference, choose "week," "month," or "Never" from the popup menu indicating how frequently to check for updates. If you would like to check for updates manually, click the button labeled "Check for updates now". If a new version of CCC is available, a window will appear indicating new features, problems resolved, etc. If your version is current, you will receive a message indicating that you are up to date.

You also can choose to be informed of beta updates. Occasionally, beta updates are provided to field test updated version of CCC to confirm that code changes resolved a particular problem. In general, beta updates are only issued when a user has discovered a problem that the software developer cannot reproduce. Therefore, you should only apply beta updates when instructed to do so by Bombich Software.

Installing an update when you have scheduled tasks

When a software update is available and you choose to download and install it, you will be prompted to temporarily unload any scheduled tasks. Because scheduled tasks run as the system administrator user, you will be prompted to authenticate to unload these scheduled tasks. When the download and installation is complete, CCC will be relaunched and will prompt you to authenticate once again to reload your scheduled tasks.

Manually installing updated versions of Carbon Copy Cloner

If you decide to manually install a newer version of CCC, be sure to disable any scheduled tasks first. The Finder will not allow you to replace the original version of CCC unless scheduled tasks have been disabled.

			Frequently Asked Questions

[CCC Help] [Browse Help Topics]

• What happened to the "Repair permissions" option?
• Can I use CCC to back up my BootCamp (Windows) partition?
• Why don't the volume capacities as reported in Disk Utility match on the source and target?
• CCC requires an HFS+-formatted target volume. Why? And how do I format my new hard drive as HFS+?
• What are "Input/output" errors, and how should I deal with them?

What happened to the "Repair permissions" option?

"Repair permissions" is not what I consider to be a task associated with backing up one's hard drive. It is at most a maintenance task, and more suitably a troubleshooting tool that should be used judiciously.

I just backed up my Boot Drive to a partition on an external Firewire Hard Disk. However, the volume capacities do not match. Should they? Should I be concerned there's more than a GB missing?

There are a couple legitimate explanations for a mismatch between the capacities reported in Disk Utility. First, when cloning using the "Incremental backup of selected items" cloning method, there is a list of items that are excluded from the backup either because they are ephemeral items regenerated every time your machine reboots, or they are not appropriate to back up or because they actually reduce the portability of your OS to another computer. Here is an exhaustive list of those items:

• .Spotlight-V100
• /.fseventsd
• /.hotfiles.btree
• /.vol/*
• /Auth.bak
• /Backups.backupdb
• /Cleanup At Startup
• /TheVolumeSettingsFolder
• .Trash
• .Trashes
• /TheFindByContentFolder
• /Shutdown Check
• Temporary Items
• /VM Storage
• /OpenFolderListDF
• /Desktop (Mac OS 9)
• /.com.apple.NetBootX
• /Volumes/*
• .VolumeIcon.icns
• /dev/*
• /automount
• /Network
• /private/var/vm/*
• /private/tmp/*

While I don't recommend it, you could modify the list of items that CCC ignores by editing the "defaults.plist" file within the CCC application bundle. Note that these items are not ignored when using the "Backup everything" cloning method.

While the exclusion of these items explains much of the disk capacity discrepancy you may discover in Disk Utility, it does not explain it all. A user suggested the following scenario after performing a "Backup everything" clone to his target drive:

Boot drive - 39.67 GB used
Backup drive - 38.55 GB used

Should I be concerned there's more than a GB missing? Could this be a swap file or something? Is there an easy way to isolate what files are not on both?

A GB seems like a lot, but it's not surprising, not for 40GB used (the discrepancy increases with the amount of data on your boot volume).

I spent about 3 months head-down in the HFS+ filesystem specification trying to figure out why the contents of a cloned volume is always less than the boot volume (and it really is only that large of a difference when the source is the boot volume). I still can't explain it entirely, however I noticed that if I booted from the cloned volume, the difference was suddenly in the reverse.

The issue is that Disk Utility (and Finder Get Info for the volume) is misleading. The value that Disk Utility reports is indeed the amount of space consumed on your hard drive, however, it is not the amount of space consumed on the drive by all the files and folders that you can see. And I'm not referring to the other files as simply "invisible", these other files and directories that make up the rest of the space you're "missing" are simply not presented to the operating system. These items are filesystem implementation details, and it isn't possible to copy them directly with file-level copying tools.

Does this mean you're losing data? Absolutely not. It's pretty easy to prove it to yourself too, just boot from your cloned volume and take a look at the capacity reports in Disk Utility. Here's an example I performed on my test machine:

** Booted from the original source volume
Source: 5,258,776,576 bytes
Clone: 5,025,562,624 bytes

**Booted from the clone volume
Source: 4,996,599,808 bytes
Clone: 5,250,097,152 bytes

Weird, eh? Having stared at this issue for three months, having developed a utility that would carefully analyze every single file that I could find and copy, I am 100% confident that I'm not losing a scrap of information with my file-level copy engine for the "Backup everything" cloning method. What I have learned and I am confident in saying is that Disk Utility can't really be used as a good measure of success for your clone. That's not to say that what it reports is wrong, it is simply misleading.

Can I use CCC to back up my BootCamp (Windows) partition?

Backing up non-HFS+-formatted volumes is not currently supported. I am investigating how to provide this support in a future release.

CCC requires an HFS+-formatted target volume. Why? And how do I format my new hard drive as HFS+?

Mac OS X is installed on an HFS+ filesystem. The HFS+ filesystem defines many types of metadata that describe non-data attributes of your files. Creation date, access control lists, permissions and ownership, Finder flags, and extended attributes are among the various metadata types defined in the HFS+ standard. To adequately back up all of your files and their associated metadata, CCC requires that your backup volume is also formatted as HFS+.

When you purchase a new hard drive, or if you have a hard drive that you use with a Windows computer, that hard drive is often pre-formatted as FAT32. CCC won't let you back up directly to the FAT32 volume (it will disable, or "gray out" the selection in the source and target menus) because it will lose some metadata.  Most notably, you'll lose ownership and permissions as well as an Access Control List settings.

Additionally, Macintoshes can only boot from hard drives partitioned with either the Apple Partition Map (APM) scheme (PowerPC- or Intel-based Macs) or the GUID Partition Table (GPT) scheme (Intel-based Macs). The hard drive icons that you see in the Finder are volumes. The partition scheme of a hard drive describes how volumes are physically defined on the hard disk. Every hard drive has exactly one partition scheme and at least one volume. When you "partition" a hard drive, you simply create multiple volumes on that hard drive.

Follow these steps to format your hard drive as an HFS+ volume:

1. Launch Disk Utility
2. Click on the hard drive device in the list on the left (the volumes have names that you see in the Finder, like "Macintosh HD" whereas the hard drive device has a name that includes the size of the hard drive and a vendor name or serial number, like "111.8 GB ST9129876A")
3. Click on the Partition tab
4. Choose "1 Partition" from the "Volume Scheme" popup menu (or more if desired).
5. Click on the "Options" button at the bottom of the partitions table and choose a partition scheme appropriate for the way you intend to use the hard drive:





6. Click on the "Apply" button
7. Choose "Mac OS Extended (Journaled)" format, then click on the Erase button at the bottom of the window

What are "Input/output" errors, and how can I resolve them?

When copying to or from damaged media, or a disk with a damaged filesystem, CCC may report "Input/output" errors. If no other major errors are encountered, CCC will produce a dialog box indicating:

"CCC detected "Input/output" errors during the clone. These errors are indicative of filesystem damage or hardware trouble with the source or target volume. Examine the CCC.log to determine the nature of these errors and consider replacing the affected hard drive if filesystem repair is unsuccessful."

Correspondingly, the CCC.log file will list the files that CCC was attempting to read or write when the error occurred:

02:13:49 rsync: read errors mapping "/Applications/Keynote.app/Contents/Resources/Themes/Shared/flowers_h.jpg": Input/output error (5)
02:14:39 rsync: read errors mapping "/Applications/Keynote.app/Contents/Resources/Themes/Shared/flowers_h.jpg": Input/output error (5)
02:18:20 rsync: read errors mapping "Users/bombich/Movies/1984.mov": Input/output error (5)
02:18:24 rsync: read errors mapping "Users/bombich/Movies/1984.mov": Input/output error (5)
02:18:24 ERROR: Users/bombich/Movies/1984.mov failed verification -- update discarded.

The exact errors may vary, and some may be duplicated. If the affected file path begins with a "/" and CCC reports a read error, it is probably your source volume (e.g. the boot volume) that is affected. Errors affecting the target volume often indicate that "mkdir" failed or other write errors occurred, or the path will indicate the name of target volume.

Occasionally these errors are reported because your filesystem is damaged, but these errors typically indicate that your hard drive is dying. You have a narrow window of opportunity to back up the data from that disk to another hard drive. Time is precious; components could fail at any moment rendering the drive completely unmountable. Read activity is stressful on a dying volume, especially a full-volume backup. When I run into these errors on a hard drive that has not been backed up, I immediately back up the files that are most important. Once the most important data is backed up, I then try to do a full-volume backup. Once all important data is backed up, I then may try a filesystem repair utility (e.g. Disk Utility or Disk Warrior) if signs of imminent faliure are not present (e.g. particulary noisy drive, or loud, repetitive clicks).

What if the dying drive's volume won't mount?
More often than not, you're completely out of luck. I provided tech support at a University many years ago and had the opportunity to witness many failed drives. Occasionally we were able to revive a hard drive for small amounts of time by letting the drive cool down (somewhere cool and dry, not cold) and then powering it up attached to a service workstation (e.g. don't attempt to boot from it, you may not have enough time). When a drive doesn't mount, it typically goes to the recycle center or to DriveSavers if the data is worth the recovery cost. If you're reading this paragraph now because you're in this situation, my heart goes out to you.

			Carbon Copy Cloner Public Source Code Credits

[CCC Help] [Browse Help Topics]

Localizations

I would like to thank the following people for their generous help in translating CCC into other languages:

• German: Martin Kowalewski
• Japanese: Tadahisa SUGISAKI
• Italian: Francesco Magariello
• Spanish: Victor Bottacco [website]
• Dutch: Alexander Henket
• French: Antoine LATOUR

Opensource Credits

Carbon Copy Cloner contains portions of source code available under the Apple Public Source License. That code may be downloaded by clicking the links below.

• vsdbutil_main.c (View my modifications: vsdbutil.h and vsdbutil.c)

View the APSL 2.0 license

Carbon Copy Cloner also includes, independently in binary form, rsync version 3.0.5pre2. rsync is made available under the GNU General Public License. Per the license requirements, the source code and my modifications may be downloaded via the links provided below. This modified software is provided at no cost and with no warranty, also per the GNU GPL.

• Download the complete rsync 3.0.5pre2 project
• Download the rsync 3.0.5pre2 patches
• Download the diff file (diff between 3.0.5pre2 + [crtimes.diff, fileflags.diff, and backup-dir-dels.diff] and my modifications)
• View the GNU GPL

Carbon Copy Cloner is not a derivative work of rsync, nor does it depend on rsync for ordinary operation. Rsync is included as a convenience and an option, and called in binary form as required.

Disclaimer

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

			CCC Release History

[CCC Help] [Browse Help Topics]

Originally published on January 18, 2002, Carbon Copy Cloner was the very first native cloning utility for Mac OS X. For version 3, Carbon Copy Cloner was completely rebuilt with a new suite of features to meet the growing needs of Mac OS X users. In addition to the fast disk-to-disk cloning, CCC is now a full-featured backup utility as well.

Among the new features in CCC 3 are:

• Support for block-level disk-to-disk clones.
• Synchronization built-in, not bolted on.
• Support for backing up across the network to another Macintosh.
• Advanced scheduling capabilities -- choose what days to run your backups and how frequently they should run. You can also defer a backup if it starts at an inopportune time.
• Now you can create a scheduled task that backs up your data whenever you attach a specific hard drive or iPod.
• The ability to drill down into folders to select exactly what gets copied and what doesn't (you can drill down indefinitely).
• A more responsive interface and the ability to stop the clone.
• More accurate feedback during the clone.
• The ability to pick up where a previously aborted backup task left off.
• More information about your volumes are available within the CCC interface.

v. 3.1.3 (21), December 8, 2008

• Fixed an issue in which the target volume would not be bootable in some cases.
• Fixed an issue in which a block-level clone would be attempted inappropriately.
• Included updated localizations including a complete French localization.
• CCC should no longer check for updates if a backup task is running.
• CCC now ignores Time Machine backup databases. Time Machine backups will not be backed up (CCC does not support backing up Time Machine backups).
• Messages indicating that a scheduled task's target disk has reappeared are now automatically dismissed after 60 seconds allowing the task to run.
• Fixed an issue that would prevent the saving of scheduled tasks upon the very first launch of CCC.
• CCC no longers permits non-HFS+ volumes as a selectable source volume (in support of the defined system requirements).
• Fixed an issue in which files or folders with special characters (e.g. "[", "]", and "*") could not be excluded in an "Incremental backup of selected items" backup task.
• Fixed an issue in which CCC would report a generic error rather then indicating that a backup task failed because there was not enough free space on the target to accommodate large files that had been modified since a previous backup.

v. 3.1.2 (20), October 13, 2008

• Resolved an issue with the syncronization engine that caused Incremental backups to fail in some cases.
• The "Backup everything" cloning method now properly handles inherited ACLs.
• The "Backup everything" cloning method is now 25% faster during a file-level copy. It consumes far lass time when backing up to an existing backup.
• Fixed a bug in which creation dates of modified files were not properly preserved on PowerPC-based Macs when using the Incremental backup method.
• I now provide more insight into how to resolve an error message caused by trying to replace an item on the backup volume that is of a different type than the item on the source volume.
• Pre and post-clone script output is now directed to the CCC.log file. CCC also aborts more gracefully when pre-clone scripts exit with a non-zero exit status.
• The Stop button in the cloning progress panel no longer has focus. Users that press the space bar to wake a dimmed display will be pleased that this action no longer aborts a backup operation.
• Fixed an issue in which CCC relied solely on the HFS+ volume UUID (Universally Unique Identifier) for identification, which, in rare cases, led to CCC trying to clone a volume to itself.
• Reformatted the Help content for easier printing. The entire set of documentation can be printed from any page in the documentation. Documentation also now opens in your favorite web browser.

v. 3.1.1 (13), July 7, 2008

• Included version 3.0.3 of rsync (minor bug fixes).
• Fixed a bug in which clicking "Proceed" when plugging in a target volume does not cause the scheduled task to proceed if that task is scheduled to back up only when the target drive is reattached.
• Fixed a bug in which extended attributes on a file would not be preserved if that file was locked on the source volume (only affected the "Backup everything" backup method).
• Fixed an issue in which CCC would not report success if minor errors were encountered. Upon encountering minor errors, CCC now reports that the backup task completed, but encountered errors. This also permits any post-backup tasks to occur, such as blessing the target volume and running post-backup scripts.
• Fixed an issue in which deferred tasks would run late if the machine slept.
• Fixed an issue in which the CCC application would not launch if it was initially installed by another user on the system.
• For the "Backup everything" cloning method, CCC no longer defaults to erasing the target device. CCC will warn if an existing OS installation on the target may conflict with the installation that is being backed up.
• Implemented support for block-level cloning to a disk image (when the source volume can be unmounted) and improved the performance of file-level backups to a disk image. These changes represent a 2-5x performance improvement.
• Disk image segmenting now works as advertised.
• Resolved an issue in which choosing to encrypt a disk image would cause CCC to hang on Leopard.

v. 3.1 (12), March 24, 2008

• Implemented rsync 3.0.0 to provide even greater fidelity when backing up using the incremental backup method
• Improved the wording of options in the interface to make it more clear what CCC is doing
• Implemented "bootability" checks -- CCC now reports whether the backup volume will be bootable based upon the options you have chosen
• CCC now offers a dialog box to opt out of a backup task that is scheduled to occur when the target volume is reattached
• Resolved an issue in which an existing disk image selected as the target would not get mounted during a "Copy everything" backup
• When creating a new sparse image during a "Copy everything" backup, the capacity of the disk image is now the same as the capacity of the source volume rather then just enough space to accommodate the files that will be copied
• Resolved issues with installing the Authentication Credentials installer package from multiple source machines on a single target machine
• Adjusted permissions of the archival folders so that admin users can modify their contents
• Adjusted permissions of target disk image so that admin users can mount it read-write
• Resolved an issue in which scheduled tasks would not run upon reboot (Leopard only)
• Resolved an issue in which a backup using the "Copy everything from source to target" method would fail soon after erasing the target volume
• CCC no longer allows the scheduling of tasks that erase the target volume
• Fixed a regression in which the "invisible" flag is not preserved when performing a backup with the "Copy everything" method (Leopard only)
• CCC no longer errantly warns the user that specifying "/" as the path on a remote source volume will overwrite the boot volume
• Resolved an issue in which specifying a path with a space in it would cause CCC to back up to the wrong location on a remote Macintosh, potentially resulting in data loss

v. 3.0.1 (11), October 23, 2007

• Fixed an issue that caused creating new disk images to fail
• Fixed an issue that would cause backup to a remote Macintosh to fail
• Fixed an issue that caused "Failed to chown" messages to appear in the log and caused CCC to report that the synchronization engine had failed
• Modification times of folders and applications are now properly preserved when using the "Copy everything" cloning method
• Fixed an issue in which locked files were not properly deleted (as necessary)
• Fixed an issue in which CCC reported that it could not enable ownership on the target volume
• CCC now explicitly disallows non-HFS volumes (this clears up confusion on what target volumes are supported)
• Fixed an issue in which CCC errantly reported that it could not archive some items during a "Copy selected items" clone
• Resolved several localization issues and included localizations for French, Russian, Korean, Swedish, and Dutch
• The Authentication Credentials Installer package no longer installs CCC's version of rsync into a location commonly in $PATH
• Minor tweak to improve performance when copying to a sparse disk image created by CCC on a network volume
• Fixed an issue that would cause some target volumes to not be bootable
• Fixed a cosmetic issue in which the amount of data copied in the CCC.log file was grossly incorrect

v. 3.0 (10), September 18, 2007 (Official non-beta release)

The change list is over 100 lines long, the items listed below are an executive summary

• Several performance and fidelity enhancements to the rsync engine
• Created a new copy engine for file-level, full-volume clones
• Resolved issues of certain normally-invisible files appearing on non-booted target volumes
• Numerous interface enhancements
• Completely redesigned the Scheduler interface
• I now provide additional statistics during the clone (time elapsed and data copied)

v. 3.0-b5 (8), March 5, 2007

• Resolved an issue with the "Check for updates now" button returning an error suggesting that you are not connected to the Internet.
• Resolved an issue where a message indicating that CCC had trouble enabling permissions on the target volume appeared even if permissions were already enabled on the target volume.
• Resolved an issue in which a backup done with the "Copy selected files" option would incorrectly modify the creation date or modification date of certain files.
• Resolved an issue where resource forks and other extended attributes would indiscriminately be copied every time a "Copy selected files" task was run, even if those items already existed on the target and had not changed.
• Fixed a cosmetic issue related to resizing the Scheduled Tasks window.
• The background tools included with CCC are now built Universal.
• Resolved an issue where repeating a disk-to-disk clone would fail indicating that you must choose a source and despite that a source and target are already selected.
• Imposed a debug log file size limit.
• The clone description is no longer updated during the clone (caused unnecessary panic among some people).
• CCC now properly prevents the unmounting of a source or target disk during a clone.
• Resolved a minor cosmetic issue related to deselecting items in the items to be copied table.
• Support for "incremental" backups -- modified and deleted files are saved to a time-stamped directory on the target.
• CCC prevents a source or target volume from being unmounted during a clone.
• Support for checksumming a "Copy selected files" operation for users running 10.4.9.
• A custom build of rsync is now included with CCC that resolves several bugs listed above.
• Included preliminary localizations for French, Japanese, Spanish, and Swedish.

v. 3.0-b4, February 16, 2007 (First public beta)

• Support for block-level disk-to-disk clones.
• Support for backing up across the network.
• The ability to drill down into folders to select exactly what gets copied and what doesn't (you can drill down indefinitely).
• A more responsive interface and the ability to stop the clone.
• More accurate feedback during the clone.
• The ability to pick up where a previously aborted backup task left off.
• More information about your disks are available within the CCC interface.
• Advanced scheduling capabilities -- choose what days to run your backups and how frequently they should run. You can also defer a backup if it starts at an inopportune time.
• Now you can create a scheduled task that backs up your data whenever you attach a specific hard drive or iPod.