Comment 0 for bug 1876334

Revision history for this message
Chris Newcomer (cnewcomer) wrote : [Focal] zsys does not clear out old snapshots, potentially filling up bpool

I had been running Focal since the March 4th and installed it via the daily ISO at that time. I opted for ZFS root during the installation process. It was mostly the reason why I went with Focal in the first place.

I ran my frequent, almost daily, apt upgrades to get the latest packages and was happy to see a lot of fixes going in during that period until the release date.

This frequent apt upgrade cadence created a snapshot in rpool/bpool every time. This feature proved useful for me since I was able to restore to a usable state using this once in the past. I was aware of the rpool snapshots, so I was cleaning them out as they built up, but I did not consider the bpool snapshots.

Eventually the small 2GB bpool will fill up with /boot changes and this did happen to me on 30-APR-2020 when I was attempting to upgrade to the latest kernel release. It gave me a cryptic error when trying to run update-initramfs, so I did a G search on the error and it pointed to a disk full situation. When I checked, I saw that only 14MB was free on bpool. I then removed all snapshots that didn't have a coordinating snapshot in rpool and that freed up about 1.2GB in bpool.

I will upload the /var/log/apt/term.log file for the time that I attempted the kernel upgrade and it failed. I will also upload a sosreport from my laptop (which has the same issue at this time without me doing any intervention). It didn't get as many apt updates, so it has free space in bpool still.

I will leave my laptop in the current state in case you need more information. I will probably send snapshot lists from both bpool and rpool on that laptop. (Once again, I did clean up rpool snapshots manually on the laptop).

Let me know if you need more information, log files, command outputs.

Great work on this package so far!
Chris