When do sparse files explode to full size, and how could you preserve them in transit? Can you copy clones or snapshots? How to preserve extended attributes?
backup
From dispatch of a new automatic backup, through computing which items need to be backed up, cleaning up snapshots and old backups, to success at the end.
APFS or HFS+? Which can Time Machine back up to? What about hard disks? Which format for use on PCs? And which are supported by Disk Utility now?
Released in Mac OS X 10.5 Leopard on 26 October 2007, it supported Time Capsules launched in January 2008, and in Big Sur could back up to APFS.
How large should the drive be to store all your backups for the next couple of years? Here’s how to work that out for Time Machine and other apps.
Most backup apps make snapshots, so why not use those instead of conventional backups? Because of the weaknesses of snapshots, as explained.
Unless you exclude them from backups, Time Machine will back up all items in iCloud Drive as long as they’re stored locally when the backup is made.
Consider the fidelity of backup copies, the speed of a backup method, and the risk of losing the contents of that backup. And test backups by restoring samples from them.
Classic TM backed up HFS+ to HFS+; current TM backs up APFS to APFS. But what if you want to back up a mixture of APFS and HFS+ volumes?
What’s in an APFS snapshot, and how the stages in its life-cycle work, from creation, through mounting and unmounting, to deletion and cleanup.
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