Note: This will erase all data on your backup disk!!!

Launch Disk Utility

Open a Finder window and navigate to Applications > Utilities and double click on Disk Utility.

The remaining steps vary considerably depending on the operating system you are running. Choose About This Mac from the Apple menu to determine your current OS, then make a selection below.

Instructions for High Sierra and later

Show All Devices

Disk Utility in High Sierra offers a very simplified view of your devices by default. Unfortunately, this hides the devices that you need to select to modify the partitioning of your backup disk. Before doing anything else in Disk Utility, choose Show All Devices from the View menu, or from the View popup button in Disk Utility's toolbar.

Select the backup disk

Click to select the disk that you would like to use for your backup. This disk should not be the same as your startup disk.

The name of a new disk will often include the manufacturer’s name (e.g. WD My Book 111D Media...). A startup disk will often include the manufacturer's serial number in the title (e.g. TOSHIBA MK50...).

Erase the backup disk

Click on the Erase button in Disk Utility's toolbar, then configure the name, format, and partitioning scheme of your backup disk. You can set the name to whatever you like, but set the Scheme to GUID Partition Map.

Choosing a Format for your destination volume

Starting in macOS High Sierra, both APFS and Mac OS Extended (Journaled) are acceptable formats for a backup of macOS 10.13 (and later). Mirroring Apple's recommendations, we recommend that you choose APFS if your destination device is a Flash storage-based device (e.g. an SSD) and will be used to back up 10.13 or higher, or if you are backing up a T2-based Mac and you intend to enable encryption on the backup. Choose Mac OS Extended (Journaled) if your destination device is a spinning-platter-based device (i.e. a hard disk drive, or HDD), or if you are backing up an operating system older than 10.13.

Click the Erase button when you are finished configuring the name, format, and partition scheme for your destination.

Your new hard drive is now ready to accept backups created by Carbon Copy Cloner!

Instructions for El Capitan and Sierra

Select the backup disk

Click to select the disk that you would like to use for your backup. This disk should not be the same as your startup disk.

The name of a new disk will often include the manufacturer’s name (e.g. WD My Book 111D Media...). A startup disk will often include the manufacturer's serial number in the title (e.g. TOSHIBA MK50...).

Erase the backup disk

Click on the Erase button in Disk Utility's toolbar, then configure the name, format, and partitioning scheme of your backup disk. You can set the name to whatever you like, but set the Format to Mac OS Extended (Journaled) and set the Scheme to GUID Partition Map, then click the Erase button.

Don't Use Time Machine

Click Don’t Use. You may use the same backup disk for both Time Machine and CCC backups, but if you do so, you must use a dedicated partition for the Time Machine backup. Otherwise Time Machine will consume all available space on the backup volume and make it impossible for CCC to use the backup volume.

Your new hard drive is now ready to accept backups created by Carbon Copy Cloner!

Instructions for Yosemite

Select the backup disk

Click to select the disk that you would like to use for your backup. This disk should not be the same as your startup disk.

The name of a new disk will often include the storage capacity and manufacturer’s name (e.g. 500.07 GB WD My Passp...). A startup disk will often include the manufacturer's serial number in the title (e.g. 320.07 GB TOSHIBA MK3255GSXF Media).

Partition the backup disk

Click on the Partition tab.

Choose 1 Partition from the Partition Layout popup menu (or more if desired).

Click on Options.

Choose GUID Partition Table, then click the OK.

Name the Volume

Format the Volume

Select Mac OS Extended (Journaled) from the Partition Format popup menu.

Click Apply.

Ensure that you have selected the correct disk for your backup drive. This step will delete all data from the selected disk. Click Partition.

Now skip ahead to the remainder of the instructions that are not OS-specific.

Related Documentation

'My disk is already formatted HFS+, why am I getting this warning?'
Video: Preparing a drive for a backup of the macOS in macOS 10.11 or higher
Video: Creating a new/additional partition (OS X 10.10 and earlier)
Support for third party filesystems (e.g. NTFS, FAT32)

Carbon Copy Cloner backups are better than ordinary backups. Suppose the unthinkable happens while you're under deadline to finish a project: your Mac is unresponsive and all you hear is an ominous, repetitive clicking noise coming from its hard drive.

With ordinary backups, you'd spend your day rushing out to a store to buy a new hard drive and then sit in front of your computer reinstalling the operating system and restoring data.

With Carbon Copy Cloner, your data and the operating system's data are all preserved on a bootable volume, ready for production at a moment's notice. When disaster strikes, simply boot from your backup and get back to using your Mac. At your convenience, replace the failed hard drive and then let CCC restore the OS, your data and your settings directly from the backup in one easy step.