Using the below zfs-auto-snapshot commands, how to specify to keep 52 weekly snapshots and infinite number of monthly snapshots?

sudo zfs set com.sun:auto-snapshot=true storage
sudo zfs set com.sun:auto-snapshot:weekly=true storage
sudo zfs set com.sun:auto-snapshot:monthly=true storage

When I specified it as a keyword or argument it failed both times:

sudo zfs set com.sun:auto-snapshot:weekly=true storage keep=52
cannot open 'keep=52': invalid dataset name

sudo zfs set com.sun:auto-snapshot:weekly=true storage --keep=52
cannot open '--keep=52': invalid dataset name

Here is a sample of one of my system's /etc/cron.d/zfs-auto-snapshot.


*/5 * * * * root /sbin/zfs-auto-snapshot -q -g --label=frequent --keep=24 //
00 * * * * root /sbin/zfs-auto-snapshot -q -g --label=hourly --keep=24 //
59 23 * * * root /sbin/zfs-auto-snapshot -q -g --label=daily --keep=14 //
59 23 * * 0 root /sbin/zfs-auto-snapshot -q -g --label=weekly --keep=4 //
00 00 1 * * root /sbin/zfs-auto-snapshot -q -g --label=monthly --keep=18 //
  • Running > /usr/sbin/zfs-auto-snapshot -q -g --label=frequent --keep=24 results in: bash: /usr/sbin/zfs-auto-snapshot: No such file or directory. If I run > which zfs-auto-snapshot, I get: /usr/local/sbin/zfs-auto-snapshot. I then tried > zfs-auto-snapshot -q -g --label=frequent --keep=24 which returned Error: The filesystem argument list is empty.. Do those commands work on Ubuntu? – Greg Jun 16 '17 at 1:37
  • Please don't run > anything, especially as root, unless you know for a fact that you really want to do this. A bare > x will truncate the file x, causing loss of data, and parameters intended for x (if it is an executable) will likely not help you there. @Dave, if you want to illustrate the shell prompt, use $ or # as those are the common symbols for ordinary user and superuser prompts, respectively. Or just leave it out entirely. – a CVn Jul 8 '17 at 13:23

You need to edit the invocation of zfs-auto-snapshot. The file should be located in /etc/cron.weekly/zfs-auto-snapshot. There a default value of 8 is set.

I personally didn't know about this tool before. What I use is zfSnap. It's available in the standard repositories.

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