zdb: failed to unpack nvlist

[SergeiD]

G'day for all!

I has one working zfs pool on our pve:

# zpool status
  pool: zfs-stor
 state: ONLINE
  scan: scrub repaired 0B in 02:49:37 with 0 errors on Mon Mar 24 21:04:39 2025
config:

        NAME                        STATE     READ WRITE CKSUM
        zfs-stor                    ONLINE       0     0     0
          raidz2-0                  ONLINE       0     0     0
            scsi-35000039c283854b9  ONLINE       0     0     0
            scsi-35000039c28386741  ONLINE       0     0     0
            scsi-35000039c283862ad  ONLINE       0     0     0
            scsi-35000039c28385485  ONLINE       0     0     0
            scsi-35000039c28386699  ONLINE       0     0     0
            scsi-35000039c28385381  ONLINE       0     0     0
            scsi-35000039c283855ed  ONLINE       0     0     0
            scsi-35000039c28386311  ONLINE       0     0     0

errors: No known data errors

I wanted to see additional information on the zfs pool, using zdb. But:

# zdb
failed to unpack nvlist
or
# zdb -b zfs-stor
zdb: can't open 'zfs-stor': No such file or directory

What's the problem? Why zdb don't see my pool? I found a hint that I need to use the -U key for zdb to specify the path to the cache:

zdb -U /path/to/zpool.cache

But where is placed the zpool.cache in the pve?

# zpool get cachefile zfs-stor
NAME      PROPERTY   VALUE      SOURCE
zfs-stor  cachefile  none       local

TIA,
SergeiD

 

[SergeiD]

G'day for all!

I've found that zdb correctly works with the '-l' (--label) key:

# zdb -l zfs-stor
------------------------------------
LABEL 0
------------------------------------
    version: 5000
    name: 'zfs-stor'
    state: 0
    txg: 987741
    pool_guid: 15374947298329400153
    errata: 0
    hostid: 1940047143
    hostname: 'pve1'
    top_guid: 8718461132375268731
    guid: 13587570952072407053
    vdev_children: 1
    vdev_tree:
        type: 'raidz'
        id: 0
        guid: 8718461132375268731
        nparity: 2
        metaslab_array: 256
        metaslab_shift: 34
        ashift: 12
        asize: 64012389711872
        is_log: 0
        create_txg: 4
        children[0]:
            type: 'disk'
            id: 0
            guid: 18321272663772959049
            path: '/dev/disk/by-id/scsi-35000039c283854b9-part1'
            devid: 'scsi-35000039c283854b9-part1'
            phys_path: 'pci-0000:4c:00.0-sas-exp0x5001c450298957bf-phy0-lun-0'
            vdev_enc_sysfs_path: '/sys/class/enclosure/8:0:8:0/ArrayDevice00'
            whole_disk: 1
            DTL: 13698
            create_txg: 4
...