SOLVED Regular snapshot deletion problem.

[rogerh]

I have a zvol with several datasets on it, and I initially set up half-hourly snapshots recursively on it, to be kept for 2 months. These were duly made, but I ran into problems (with the Time Machine doing the backup all over again issue) which led to one of the datasets with a quota getting full. Therefore I destroyed all but the previous few days' snapshots, reset the time to keep snapshots to 2 weeks and saved the snapshot task. It is now more than two weeks and no snapshots have been destroyed. Not only the couple of days already present when I restarted the snapshot task, but some made since restart but more than two weeks ago. What might I be doing wrong?

Roger

Edit. HP N54L Microserver, 8GB RAM, 4 1TB disks in RAIDZ2, was 9.2.1.5, two days ago upgraded to 9.2.1.6.

 

[dlavigne]

Are the snapshots not being destroyed on the local system or on the remote system (e.g. are these being replicated)?

 

[rogerh]

Are the snapshots not being destroyed on the local system or on the remote system (e.g. are these being replicated)?

No, no replication, just the local system. (Sometime I must find out how replication works in this respect, but at the moment that is not my problem!)

 

[rogerh]

Can I ask a supplementary question to help me troubleshoot, as no-one seems to have a ready answer? How does the snapshot task recognise its own snapshots, so it can cull them but not remove ad hoc snapshots made by the operator? Do they have a tag, different permissions, or are they listed somewhere?

 

[rogerh]

Can no-one help on this? Can it be a bug to do with changing the time to keep snapshots for an existing task? Has anyone done that and it worked?

 

[dlavigne]

This sounds like a bug then. Please create a bug report at bugs.freenas.org and post the issue number here.

 

[rogerh]

OK, I think I'll check if it is solvable by deleting all snapshots and tasks and starting again, and whether it is then reproducible, first.

 

[rogerh]

Update. I think there was no bug, just my own error of observation. Or else it disappeared when I deleted them all and rebooted. I am uncertain. The confirmed behaviour is a little unexpected, in that the snapshots retain the lifetime they had when they were created. Any snapshot created by a task to last two months is kept for two months even if the task is later changed to keep newly created snapshots for only two weeks. For anyone else as unobservant as me, the lifespan of the task-created snapshot is stored in the last few characters of its filename!