So after spending weeks configuring my Ubuntu 22.04 LTS, installing all the things I need, making it exactly as I wanted, I started experiencing some random freezes of my netbook (i5 11th gen with 8gb of RAM).

And now I discovered that the random freezes of my laptop (usually under heavy load) are because Ubuntu still invites to use ZFS, and at the same time somehow thinks that 2gb of swap are always good. And apparently they ignore that since 4 years is known that ZFS is not good to have swap partitions as they don't work: https://github.com/openzfs/zfs/issues/7734

Default Ubuntu installation makes a separate 2gb swap partition and then fills the rest of hard drive with ZFS partition. I need more than 2gb of swap, so I created a new ZFS volume (following official ZFS docs) for swap, enabled it, and discovered that when is used it slows down the system under low load, and literally grinds to a halt (as explained in the Github issue) under heavy loads.

I've been able to replicate the deadlock I experience with stress-ng and heavy RAM usage stress test.

Now THE QUESTION: what can I do?

I do need 16gb of swap (my ram is 8), my disc doesn't have free space: efi partition, swap partition of 2gb, then all the rest is ZFS. What can I do? Resizing ZFS seems not possible, as it seems there's no solution to the problem of using as swap a ZFS volume.

Any suggestion apart having to literally re-do and reinstall everything using exf4 this time? :-(

  • 2
    Your last sentence is correct. Using ext4 is the simple solution. Commented Jun 20, 2022 at 0:13
  • @WinEunuuchs2Unix yeah but that means literally reinstalling everything…would take forever…
    – opoloko
    Commented Jun 20, 2022 at 7:38
  • Sadly that is not feasible now, as this is zfs. Anyway, since a few days I switched from GNOME to Sway as it's much more efficient and fast (and fun!), and I'm not experiencing anymore the locks. Will need to do more targeted tests, but part of the problem might be linked to other posts I saw about Gnome-shell locking up under heavy load.
    – opoloko
    Commented Jun 29, 2022 at 10:19
  • After some more time, I moved to bare wayland with Sway, also disabling gdm and free from any gnome related stuff. No more locks, and my netbook is so much faster. Obviously the problem is much mitigated using a much lighter graphical system.
    – opoloko
    Commented Jul 10, 2022 at 0:35


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