Periodic snapshots tasks: no purge of old snapshots

[ECC]

Hi,
i enabled a periodic snapshot task for my pool. I configured "2 weeks" for "keep snapshot for". However, snapshots older than 2 weeks are still stored on my pool? That fills up my pool very quickly...

 

[Samuel Tai]

Did you change the naming scheme during the 2 weeks? That will affect the ability of the snapshot task to clear out older snapshots, which won't match the new naming scheme.

 

[ECC]

Did you change the naming scheme during the 2 weeks?

i just edited the schedule but not the naming schema

Is there an easy way to delete a huge amount of snapshots at one time? Due to missing automatic purge option of truenas, i have now almost 100k of Snapshots...And I don't want to delete them one by one (truenas gui is only showing 15 at a time)

 

[blanchet]

For mass deletion, you can use the command line. For example to delete all snapshots with @auto-2020- in their name

The first time, run in dry-run mode (option -n) and and print some information (-p) to check that the command is correct. (it will delete nothing)

Code:

for s in `zfs list -r -t snap -H -o name tank1/mydataset | grep @auto-2020-` ; do
    zfs destroy -np $s ;
done

If it is OK, you can remove the -n option, to delete the snapshot

Code:

for s in `zfs list -r -t snap -H -o name tank1/mydataset | grep @auto-2020-` ; do
    zfs destroy -p $s ;
done

If you have 100K snapshots to delete, it will take a while.

 

[ECC]

Code:
for s in `zfs list -r -t snap -H -o name tank1/mydataset | grep @auto-2020-` ; do
zfs destroy -np $s ;
done

Thank you, i think it worked (with -n). But is there an option to delete all snapshots that are older than timestamp X ? (e.g. X = @auto-2021-02-09_09-11)

 

[blanchet]

I think that there is no direct command to delete all snapshots older than a timestamp, so you have to write your own script to do it.
Therefore, it would be easier to delete only the oldest snapshots, because you can iterate several times.

To dry-run the deletion of the 1000 oldest snapshots

Code:

zfs list -H -t snapshot -o name -S creation -r <datasetname> | tail --lines=1000 | xargs -n 1  zfs destroy -np

When you are OK, just remove the -n option

Code:

zfs list -H -t snapshot -o name -S creation -r <datasetname> | tail --lines=1000 | xargs -n 1  zfs destroy -p

Reference:

ZFS delete oldest n snapshots - Technicus

I came across a need to trim old ZFS snapshots. These are my quick and dirty notes on how I accomplished it. Basic syntax taken from here: zfs list -H -t snapshot -o name -S creation -r <dataset name> | tail -10 You can omit the -r <dataset name> if you want to query snapshots … Continue reading...

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