ZEVO support for Time Machine

Can I use a ZEVO-managed USB hard disk for Time Machine backups?

ZFS dedup

Will ZEVO and Time Machine give me de-duplication (which is sorely missing from Time Machine on HFS+, especially if you backup multiple machines to the same disk)?


In the Time Machine pane of System Preferences, add any ZFS dataset.

For the first backup to that dataset, the operating system will:

  1. create a sparse bundle disk image (….sparsebundle) at the root of that dataset
  2. attach the image, after which you'll see a volume named Time Machine Backups.

For each subsequent backup to that dataset, the OS will:

  1. attach the image, after which you'll see the Time Machine Backups volume.

Time Machine routines with ZFS are similar or identical to the routines that apply when backing up to a device – such as an Apple Time Capsule – that uses AFP.

How can one recover from TM after new/reinstallation? New OS installation knows nothing about ZFS to TM image is unreachable.

  • Good point. Probably only works in combination with a file server (as a restore over the network), or by copying the sparse bundles over to a disk in a supported format. – Thilo Feb 12 '12 at 11:27
  • Please: the question about restoration should be separate. There will be a multiple answers, which could become confusing under the opening questions about backup. – Graham Perrin Jul 3 '12 at 2:57
  • I refuse to think about restoration separate from backup. What is the point of a backup if not to later restore it? – Thilo Jul 3 '12 at 7:18
  • No offence intended. I may revisit this question after the banner of changes, which appeared around the time of WWDC, is lifted from the ZEVO web site. – Graham Perrin Jul 3 '12 at 20:05

Time Machine backups can only be stored on HFS+ volumes. The reason is that Time Machine relies on the ability to create new hard links to existing directories, which you cannot do in ZFS.

  • 1
    How about HFS+ in a sparse bundle on ZFS? This is how Time Machine works over the network, right? Would that work (and give me the benefits of de-duplication and encryption)? – Thilo Feb 8 '12 at 23:55
  • @Thilo: Yes, in principle, that should work. As far as de-duplication and encryption go, I don't remember from what ZFS versions those are available. But if Zevo offers them, you should be OK. – Harald Hanche-Olsen Feb 9 '12 at 12:48
  • Wish for the restore interface of Time Machine to work with ZFS snapshots … a fuller answer will fit better under a question about restoration. – Graham Perrin Jul 3 '12 at 3:22

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