I am a daily Ubuntu user, and I’ve been been one since 10.04. The use of Snaps in 22.04 took me for a very unhappy drive down frustration lane recently. Around February 2023, both Firefox and Thunderbird appeared with display rendering problems, like the were using bad video driver code. But also, Thunderbird became unkillable. It became a zombie process when I tried to exit it. So not only was my Xubuntu system almost entirely freakin’ useless for normal communications–it was shit for researching how to fix the problem: no browser!

So I tried using Chromium and…it was also display garbage as well! I immediately worried that I was seeing DRAM problems and immediately ordered a new kit of RAM that was well reviewed for AMD platforms.

…and while that solved one of my basic overclocking problems (it was able to use the XMP profile it advertized) it did not solve what must have been a library problem.

I uninstalled the Snap version of Firefox and found a PPA. That solved the display corruption. I uninstalled the Ubuntu mainline thunderbird, tried and uninstalled the Thunderbird snap, and settled on the Thunderbird PPA: no screen corruption.

The next problem was the dmesg error: PANIC: zfs: accessing past end of object

That error presaged entire application lockup and inability to kill the process. There were no ZFS scrub errors. There was no problem doing a zfs send. This is an open ZFS bug, possibly caused by some combination of compression and non-standard blocksize. Having maintained a dozen ZFS based systems with a variety of parameters, this was chilling.

The bug is still open.

However, I was able to do a zfs send of my thunderbird file system to a different zvol, and then rsync the content back to a new zvol on master media. This was a success!