I too solved this by force unmounting my rpool-ssd pool, zfs export -f rpool-ssd, then found files in /rpool-ssd, once removed things mounted on boot correctly. Its a bit tricky because proxmox auto mounts things again so I had to be quick, but you can probably stop the auto importer to see whats in the mount directory and ensure its clean, and removing the zpool.cache
UPDATE:
Still creates a bad zpool.cache each time, final brute force solution is add this to root cron so that it regenerates zpool.cache at reboot.
* * * * * /usr/bin/rm -f /etc/zfs/zpool.cache
I tried removing zpool.cache with a systemd shutdown script which would be ideal but no joy, and doing it
@reboot didn't work, doing it with a
@reboot sleep(120); rm .... was also unreliable. This is a horrible kludge, any improvements welcome but it does work
So basically without this cludge, removing zpool.cache and rebooting means everything mounts ok next boot, but the subsequent boot I then see my ssd partitions are not mounted and you again need to remove the cache file and reboot.
