Using Cloning as a Backup Strategy
Cloning is more than a backup, it’s a functionally-identical copy, a distinction that is particularly relevant for your boot drive (system and applications): you can start the Mac from the clone. But it’s also useful for efficiently backing-up any volume.
My preferred way to backup is with a large external 2TB or 3TB drive, so that I can backup everything to one drive. I backup both my Boot drive (system and applications, mail, calendar, etc), as well as my data (Master volume).
Step by step
To backup my two desktop volumes Boot and Master onto a single external hard drive:
- Partition the external backup drive into BootClone and MasterClone. This need only be done once, the first time. Subsequent backups it’s ready to go.
- Clone Boot to BootClone.
- Clone Master to MasterClone.
- You now have a bootable backup drive with all your stuff. Store the backup drive somewhere safe, away from the computer.
The cloning process takes time in proportion to how much data is present, so clear out any files you don’t need, and empty the trash first. In most cases, cloning is smart enough to only copy what has changed.
My preference is to append the date and time to the volume name of the clone, so that I know when I made it.
Cloning with Carbon Copy Cloner
Shown below is the window for Carbon Copy Cloner, one of several programs that can make a clone.
Select your existing drive (“Source Disk”) and select the new drive (“Target Disk”), then click thebutton.
As shown below, the boot volume Master is being cloned to MasterClone-2011-0120-1335. Be careful not to clone the backup drive to the original!
The cloning process will take time proportional to how much data you have on the drives, the speed of each drive, etc. If this is an update, the process can be very quick, since usually only changed files need be copied.