This article is for an older version of CCC. You can find the latest version here.
Product: 
ccc4

Does CCC have to be running for a scheduled task to run?

No. Once you have saved your tasks, you can quit CCC. Even if tasks are running, it's OK to quit CCC -- they will continue to run. A helper application, named "com.bombich.ccchelper" will be running quietly in the background, handling task operations. This helper application also loads automatically when you restart your computer, so you don't have to launch CCC again unless you want to make changes to your task configurations or scheduling.

What happens if no one is logged in when a task is scheduled to run?

The scheduled task will run whether someone is logged in to the machine or not. You can also log in or log out while tasks are running and the tasks will continue to run.

Will CCC run when the computer is turned off?

If your backup task is configured to "Wake or power on the system", CCC will schedule a "Wake or power on" event with the Power Management service and your system will turn on shortly before the task is scheduled to run.

FileVault exception

There is one notable exception to powering on the system for a scheduled task: If you have FileVault enabled on your startup disk, your computer will turn on, but it will not proceed past the FileVault authentication prompt. It is not possible for CCC to subvert this security feature. After a certain amount of time with no user input, your system will turn itself back off. This limitation is applicable only when the system is turned off; CCC can wake a system with FileVault protection enabled and proceed to run a backup task.

Related Documentation

Will CCC run when the my laptop's lid is closed?

If your laptop is running on battery power, the system will not wake while the lid is closed and CCC backup tasks will not run. If your laptop is plugged in to AC power, then CCC can wake the system to start your scheduled task if the lid is closed. See the section above for the settings that indicate whether a task can wake the system.

How is system sleep handled?

By default, CCC will wake your computer when your tasks are scheduled to run. You can change this setting in the Runtime Conditions section when scheduling a task.

Related Documentation

Why does my laptop sometimes go to sleep during a backup task?

If your Mac is a laptop, note that CCC will only be able to wake the system or prevent idle sleep if the system is running on AC power. CCC (nor any application) cannot keep the system awake while running on battery power -- macOS aggressively sleeps the system if there is no user activity while running on battery power.

Why does my screen turn on shortly before a backup task starts?

By default, CCC schedules a wake event to occur 15 seconds before a scheduled task is configured to run. Whether the system is sleeping or not, macOS turns on the display when a scheduled wake event occurs, and there is nothing that CCC can do to prevent this. If you prefer that your display does not turn on, e.g. in the middle of the night, use the Run this task when the system next wakes setting instead to have CCC tasks run during macOS Dark Wake cycles (aka PowerNap, aka Maintenance Wake).

What if the backup drive is not available when a task is scheduled to run?

If your backup drive is attached to your Mac and unmounted, CCC will attempt to mount the backup volume, then proceed with the backup task if that is successful. If the volume cannot be mounted or is not attached to your Mac, CCC will, by default, report an error, then run the task immediately when the backup disk is reattached to your Mac. You can fine-tune CCC's handling of this scenario using the options at the bottom of the Scheduler panel.

Can I stop a backup task before it finishes?

Yes, you can stop the backup task at any time. The next time you run the backup task, CCC will copy only the files that have changed or were missed since the last backup task.

How do scheduled tasks "work"?

Carbon Copy Cloner tasks are managed by a background helper application named "com.bombich.ccchelper". Task configuration files are stored in /Library/Application Support/com.bombich.ccc/Tasks. When the helper application is loaded (i.e. on startup, or when you save your first CCC backup task), it will read each of the task configuration files and schedule it as required. You should not make changes to task configuration files directly.

How can I disable/suspend a task?

If CCC's sidebar is not revealed, reveal it by choosing Show Sidebar from CCC's View menu. To disable a task, right-click on that task in the sidebar and choose Disable from the contextual menu. Use the same procedure to re-enable the task. If you would like to disable all tasks, choose Disable all tasks... from the CCC menubar application, or hold down Command+Option and choose Disable All Tasks & Quit from the Carbon Copy Cloner menu.