Boot errors regarding ZFS - what does this mean?

[rakurtz]

I saw some red line when i booted my machine. Using systemctl --failed it showed the errors below.

My zfs pool "data" appears and seems to be running fine. Since i had some performance issues with that pool i was researching for possible issues. But i could sole these by turning off all controller's caches. But (still) the error message is shown at boot time...

Any ideas?

root@pmone:~# systemctl --failed
  UNIT                    LOAD   ACTIVE SUB    DESCRIPTION                                                                         
● zfs-import@data.service loaded failed failed Import ZFS pool data                                                                 

LOAD   = Reflects whether the unit definition was properly loaded.
ACTIVE = The high-level unit activation state, i.e. generalization of SUB.
SUB    = The low-level unit activation state, values depend on unit type.

1 loaded units listed. Pass --all to see loaded but inactive units, too.
To show all installed unit files use 'systemctl list-unit-files'.
root@pmone:~# systemctl status zfs-import@data.service
● zfs-import@data.service - Import ZFS pool data
   Loaded: loaded (/lib/systemd/system/zfs-import@.service; enabled; vendor preset: enabled)
   Active: failed (Result: exit-code) since Fri 2021-02-05 17:47:39 CET; 1h 2min ago
     Docs: man:zpool(8)
  Process: 1578 ExecStart=/sbin/zpool import -N -d /dev/disk/by-id -o cachefile=none data (code=exited, status=1/FAILURE)
 Main PID: 1578 (code=exited, status=1/FAILURE)

Feb 05 17:47:39 pmone systemd[1]: Starting Import ZFS pool data...
Feb 05 17:47:39 pmone zpool[1578]: cannot import 'data': no such pool available
Feb 05 17:47:39 pmone systemd[1]: zfs-import@data.service: Main process exited, code=exited, status=1/FAILURE
Feb 05 17:47:39 pmone systemd[1]: zfs-import@data.service: Failed with result 'exit-code'.
Feb 05 17:47:39 pmone systemd[1]: Failed to start Import ZFS pool data.

 

[Stoiko Ivanov]

hmm - could you please share the output of:

zpool status
zpool import

 

[rakurtz]

this is the output of zpool status:

root@pmone:~# zpool status
  pool: data
state: ONLINE
  scan: none requested
config:

    NAME                                       STATE     READ WRITE CKSUM
    data                                       ONLINE       0     0     0
      raidz2-0                                 ONLINE       0     0     0
        ata-TOSHIBA_MG04ACA400NY_X0O1KGYNF7DE  ONLINE       0     0     0
        ata-TOSHIBA_MG04ACA400NY_X0O5KCZSF7DE  ONLINE       0     0     0
        ata-TOSHIBA_MG04ACA400NY_X0O5KCZRF7DE  ONLINE       0     0     0
        ata-TOSHIBA_MG04ACA400NY_X0O1KGYMF7DE  ONLINE       0     0     0
        ata-TOSHIBA_MG04ACA400NY_X0O1KGYHF7DE  ONLINE       0     0     0
        ata-TOSHIBA_MG04ACA400NY_X0O5KCZZF7DE  ONLINE       0     0     0
        ata-TOSHIBA_MG04ACA400NY_X0O1KGYJF7DE  ONLINE       0     0     0
        ata-TOSHIBA_MG04ACA400NY_X0O5KCZPF7DE  ONLINE       0     0     0

errors: No known data errors

Zpool import shows this:

zpool import
no pools available to import

We have no errors on that Maschine. I just see the boot log error message.

 

[Stoiko Ivanov]

What would zpool import do?

without arguments it should only print the pools which are available for import (but not imported) - see the manpage (`man zpool`) - but I understand that you're cautious on a production environment.
zpool import does also cause some IO-load since it scans the available disks.

Since the pool got imported anyways it might be simply a timing issue - Check the system journal since boot - the error messages you posted in your original post should appear there - and then search if the pool got imported before of after the messages:

journalctl -b

 

[rakurtz]

Yeah it might be a timing issue. After the line with the errors there are some more (successful) boot tasks regarding ZFS:

Feb 05 17:47:39 pmone zpool[1578]: cannot import 'data': no such pool available
Feb 05 17:47:39 pmone systemd[1]: zfs-import@data.service: Main process exited, code=exited, status=1/FAILURE
Feb 05 17:47:39 pmone systemd[1]: zfs-import@data.service: Failed with result 'exit-code'.
Feb 05 17:47:39 pmone systemd[1]: Failed to start Import ZFS pool data.
Feb 05 17:47:43 pmone systemd[1]: Started Import ZFS pools by cache file.
Feb 05 17:47:43 pmone systemd[1]: Reached target ZFS pool import target.
Feb 05 17:47:43 pmone systemd[1]: Starting Wait for ZFS Volume (zvol) links in /dev...
Feb 05 17:47:43 pmone systemd[1]: Starting Mount ZFS filesystems...
Feb 05 17:47:43 pmone zvol_wait[5262]: No zvols found, nothing to do.
Feb 05 17:47:43 pmone systemd[1]: Started Wait for ZFS Volume (zvol) links in /dev.
Feb 05 17:47:43 pmone systemd[1]: Reached target ZFS volumes are ready.
Feb 05 17:47:43 pmone systemd[1]: Started Mount ZFS filesystems.
Feb 05 17:47:43 pmone systemd[1]: Reached target Local File Systems.

But there's no explicit line saying that importing of data was successful.

 

[Stoiko Ivanov]

hm - without the complete log it's difficult to see what's potentially causing this (with the complete log there's at least a greater chance)

but you can also disable the `zfs-import@data.service` if the system boots fine for you without it.

 

[C-Fu]

hm - without the complete log it's difficult to see what's potentially causing this (with the complete log there's at least a greater chance)

but you can also disable the `zfs-import@data.service` if the system boots fine for you without it.

And how do I do that?
Related to my issue I think https://forum.proxmox.com/threads/h...iled-to-start-import-zfs-pool-zfu-help.96013/