Password not asked at boot for encrypted pool

[educongo]

Hello.

I've a proxmox server installed on a encrypted zfs rpool https://openzfs.github.io/openzfs-docs/Getting%20Started/Debian/Debian%20Bullseye%20Root%20on%20ZFS.html and another encrypted pool (datapool) where virtual disks are kept.

In the past whenever the system booted i was prompted twice to write the passphrases (one for the rpool and one for the datapool).

After an upgrade i couldn't boot any kernel so i rolled-back to a previous snapshot.

Now, whenever the system boots I'm not prompted for the second password (the datapool one).

Despite this i see

Jul 29 22:58:01 proxmox2 systemd[1]: Starting Load ZFS key for datapool...
Jul 29 22:58:01 proxmox2 systemd[1]: Finished Load ZFS key for datapool.
Jul 29 22:58:01 proxmox2 systemd[1]: datapool.mount: Directory /datapool to mount over is not empty, mounting anyway.
Jul 29 22:58:01 proxmox2 systemd[1]: Mounting /datapool...
Jul 29 22:58:01 proxmox2 mount[1786]: filesystem 'datapool' cannot be mounted, unable to open the dataset
Jul 29 22:58:01 proxmox2 systemd[1]: datapool.mount: Mount process exited, code=exited, status=1/FAILURE
Jul 29 22:58:01 proxmox2 systemd[1]: datapool.mount: Failed with result 'exit-code'.
Jul 29 22:58:01 proxmox2 systemd[1]: Failed to mount /datapool.
Jul 29 22:58:01 proxmox2 systemd[1]: Dependency failed for /datapool/subvol-179-disk-0.
Jul 29 22:58:01 proxmox2 systemd[1]: datapool-subvol\x2d179\x2ddisk\x2d0.mount: Job datapool-subvol\x2d179\x2ddisk\x2d0.mount/start failed with result 'dependency'.
Jul 29 22:58:01 proxmox2 systemd[1]: Dependency failed for /datapool/subvol-134-disk-0.
Jul 29 22:58:01 proxmox2 systemd[1]: datapool-subvol\x2d134\x2ddisk\x2d0.mount: Job datapool-subvol\x2d134\x2ddisk\x2d0.mount/start failed with result 'dependency'.
Jul 29 22:58:01 proxmox2 systemd[1]: Dependency failed for /datapool/subvol-118-disk-0.
Jul 29 22:58:01 proxmox2 systemd[1]: datapool-subvol\x2d118\x2ddisk\x2d0.mount: Job datapool-subvol\x2d118\x2ddisk\x2d0.mount/start failed with result 'dependency'.
Jul 29 22:58:01 proxmox2 systemd[1]: Dependency failed for /datapool/home.
Jul 29 22:58:01 proxmox2 systemd[1]: datapool-home.mount: Job datapool-home.mount/start failed with result 'dependency'.
Jul 29 22:58:01 proxmox2 systemd[1]: Dependency failed for /datapool/subvol-177-disk-0.
Jul 29 22:58:01 proxmox2 systemd[1]: datapool-subvol\x2d177\x2ddisk\x2d0.mount: Job datapool-subvol\x2d177\x2ddisk\x2d0.mount/start failed with result 'dependency'.
Jul 29 22:58:01 proxmox2 systemd[1]: Dependency failed for /datapool/subvol-173-disk-0.
Jul 29 22:58:01 proxmox2 systemd[1]: datapool-subvol\x2d173\x2ddisk\x2d0.mount: Job datapool-subvol\x2d173\x2ddisk\x2d0.mount/start failed with result 'dependency'.
Jul 29 22:58:14 proxmox2 zed: eid=12 class=config_sync pool='datapool'
Jul 29 22:58:14 proxmox2 zed: eid=13 class=pool_import pool='datapool'
Jul 29 22:58:14 proxmox2 zed: eid=15 class=config_sync pool='datapool'

in the logs.

The problem that i can't understand is why i'm not being prompted for the second password since load-key is being called for the datapool, as per logs.

Some more info:
zfs get encryption datapool
NAME PROPERTY VALUE SOURCE datapool encryption aes-256-gcm -

zfs get encryption rpool
NAME PROPERTY VALUE SOURCE rpool encryption aes-256-gcm -

cat /etc/zfs/zfs-list.cache/datapool

datapool /datapool on on on on on off on off datapool prompt - - - - - - - -
datapool/home /datapool/home on on on on on off on off datapool none - - - - - - - -
datapool/subvol-118-disk-0 /datapool/subvol-118-disk-0 on on on on on off on off - none - - - - - - - -
datapool/subvol-134-disk-0 /datapool/subvol-134-disk-0 on on on on on off on off - none - - - - - - - -
datapool/subvol-173-disk-0 /datapool/subvol-173-disk-0 on on on on on off on off - none - - - - - - - -
datapool/subvol-177-disk-0 /datapool/subvol-177-disk-0 on on on on on off on off - none - - - - - - - -
datapool/subvol-179-disk-0 /datapool/subvol-179-disk-0 on on on on on off on off - none - - - - - - - -

Could someone please help me?

Thank you.

Best regards

[educongo]

Hello again.

A closer reading of the site https://wiki.archlinux.org/title/ZFS#Configuration led me to the solution:

# zpool set cachefile=/etc/zfs/zpool.cache <pool>