Apparently I found a solution to this problem.
N. B. This is not about using ZFS as a Time Machine target volume! (See https://openzfsonosx.org/wiki/Time_Machine_Backups for using ZFS as backup target.)
This is about backing up ZFS volumes with Time Machine!
Here is how it works:
Either create a ZFS pool and turn on HFS mimic
- Code: Select all
sudo zfs set com.apple.mimic_hfs=on myPool
or create a ZFS pool with a HFS+ or APFS zvol on top:
https://openzfsonosx.org/wiki/Time_Mach ... kups#zvols
Open Terminal.app and do this:
1. First we check for demonstration purposes if the volume is currently backed up:
- Code: Select all
tmutil isexcluded /Volumes/myPool
[Excluded] /Volumes/myPool
2. Now we use tmutil to include the pool:
- Code: Select all
sudo tmutil removeexclusion -v /Volumes/Zetes
Password:
N. B.: This does not change the appearance in the Time Machine control panel – it is still greyed out.
3. Now we check the backup status again:
- Code: Select all
isexcluded /Volumes/Zetes
[Included] /Volumes/Zetes
Voilà!
Backing up and restoring a 2 GB iPhoto .photolibrary to and from Time Machine worked with HFS mimic and an APFS volume flawlessly.
I didn’t test a HFS+ zvol on top of HFS, but I assume it works as well.