Label unpacking failures

[grahamperrin]

How might we interpret the label-related failures for this pool's two cache vdevs (L2ARC)?

root@mowa219-gjp4-8570p-freebsd:~ # zdb -l /dev/ada0p3.eli
------------------------------------
LABEL 0 
------------------------------------
    version: 5000
    name: 'august'
    state: 0
    txg: 1466991
    pool_guid: 1913339710710793892
    errata: 0
    hostname: ''
    top_guid: 18223107463529918695
    guid: 18223107463529918695
    vdev_children: 1
    vdev_tree:
        type: 'disk'
        id: 0
        guid: 18223107463529918695
        path: '/dev/ada0p3.eli'
        phys_path: 'id1,enc@n3061686369656d30/type@0/slot@1/elmdesc@Slot_00/p3/eli'
        whole_disk: 1
        metaslab_array: 256
        metaslab_shift: 33
        ashift: 12
        asize: 982745612288
        is_log: 0
        DTL: 951
        create_txg: 4
    features_for_read:
        com.delphix:hole_birth
        com.delphix:embedded_data
    labels = 0 1 2 3 
root@mowa219-gjp4-8570p-freebsd:~ # zpool status august
  pool: august
 state: ONLINE
  scan: scrub repaired 0B in 02:44:47 with 0 errors on Sun Dec 12 06:14:24 2021
config:

        NAME                STATE     READ WRITE CKSUM
        august              ONLINE       0     0     0
          ada0p3.eli        ONLINE       0     0     0
        cache
          gpt/cache-august  ONLINE       0     0     0
          gpt/duracell      ONLINE       0     0     0

errors: No known data errors
root@mowa219-gjp4-8570p-freebsd:~ # geom part show -l da0
=>      34  60437425  da0  GPT  (29G)
        34  60437425    1  cache-august  (29G)

root@mowa219-gjp4-8570p-freebsd:~ # geom part show -l da1
=>      34  32358333  da1  GPT  (15G)
        34      2014       - free -  (1.0M)
      2048  32356319    1  duracell  (15G)

root@mowa219-gjp4-8570p-freebsd:~ # zdb -l /dev/da0
failed to unpack label 0
failed to unpack label 1
failed to unpack label 2
failed to unpack label 3
root@mowa219-gjp4-8570p-freebsd:~ # zdb -l /dev/da1
failed to unpack label 0
failed to unpack label 1
------------------------------------
LABEL 2 (Bad label cksum)
------------------------------------
    version: 5000
    state: 4
    guid: 8248197705860927698
    labels = 2 
failed to unpack label 3
L2ARC device header not found

root@mowa219-gjp4-8570p-freebsd:~ # zpool iostat -v august 3
                      capacity     operations     bandwidth 
pool                alloc   free   read  write   read  write
------------------  -----  -----  -----  -----  -----  -----
august               258G   654G     13     20   247K   519K
  ada0p3.eli         258G   654G     13     20   247K   519K
cache                   -      -      -      -      -      -
  gpt/cache-august  21.9G  6.96G     33      0   920K  46.1K
  gpt/duracell      6.99G  8.43G     14      0   424K  46.9K
------------------  -----  -----  -----  -----  -----  -----
                      capacity     operations     bandwidth 
pool                alloc   free   read  write   read  write
------------------  -----  -----  -----  -----  -----  -----
august               258G   654G     76      0   949K  5.31K
  ada0p3.eli         258G   654G     76      0   949K  5.31K
cache                   -      -      -      -      -      -
  gpt/cache-august  21.9G  6.96G    465      0  11.0M      0
  gpt/duracell      6.99G  8.43G    212      0  5.32M      0
------------------  -----  -----  -----  -----  -----  -----
                      capacity     operations     bandwidth 
pool                alloc   free   read  write   read  write
------------------  -----  -----  -----  -----  -----  -----
august               258G   654G    131     32  4.96M   493K
  ada0p3.eli         258G   654G    131     32  4.96M   493K
cache                   -      -      -      -      -      -
  gpt/cache-august  21.9G  6.96G    318      0  10.0M      0
  gpt/duracell      6.99G  8.43G    130      0  4.98M      0
------------------  -----  -----  -----  -----  -----  -----
^C
root@mowa219-gjp4-8570p-freebsd:~ # zfs --version
zfs-2.1.99-FreeBSD_g269b5dadc
zfs-kmod-2.1.99-FreeBSD_g269b5dadc
root@mowa219-gjp4-8570p-freebsd:~ # uclcmd get --file /boot/loader.conf openzfs_load
"NO"
root@mowa219-gjp4-8570p-freebsd:~ # freebsd-version -kru
14.0-CURRENT
14.0-CURRENT
14.0-CURRENT
root@mowa219-gjp4-8570p-freebsd:~ # uname -aKU
FreeBSD mowa219-gjp4-8570p-freebsd 14.0-CURRENT FreeBSD 14.0-CURRENT #116 main-n251146-d109559ddbf: Mon Nov 29 14:34:59 GMT 2021     root@mowa219-gjp4-8570p-freebsd:/usr/obj/usr/src/amd64.amd64/sys/GENERIC-NODEBUG  amd64 1400043 1400043
root@mowa219-gjp4-8570p-freebsd:~ # geom disk list da0
Geom name: da0
Providers:
1. Name: da0
   Mediasize: 30943995904 (29G)
   Sectorsize: 512
   Mode: r1w1e3
   descr: Kingston DataTraveler 3.0
   ident: E0D55EA1C84FF390A9500FDA
   rotationrate: unknown
   fwsectors: 63
   fwheads: 255

root@mowa219-gjp4-8570p-freebsd:~ # geom disk list da1
Geom name: da1
Providers:
1. Name: da1
   Mediasize: 16567500800 (15G)
   Sectorsize: 512
   Mode: r1w1e3
   descr: Generic Flash Disk
   ident: YTAI0012080818233298
   rotationrate: unknown
   fwsectors: 63
   fwheads: 255

root@mowa219-gjp4-8570p-freebsd:~ # hw-probe -all -upload
Probe for hardware ... Ok
Reading logs ... Ok
Uploaded to DB, Thank you!

Probe URL: https://bsd-hardware.info/?probe=44d3e7366c
root@mowa219-gjp4-8570p-freebsd:~ # 

Whatever's wrong with (or affecting) the labels, as far as I can tell there's no day-to-day impact on usefulness of the devices for L2ARC purposes:

• read bandwidth (shown above) is fine, and there are occasional writes to both devices.

[rincebrain]

You should probably examine the partitions and not the whole disks, as the partitions are, I think, what's in the pool.

For reference, here's the minimal label that I got on a test pool (cache, log, and spare devices get minimal labeling compared to "normal" vdev types):

------------------------------------
LABEL 0
------------------------------------
    version: 5000
    state: 4
    guid: 7023019539688364328
    labels = 0 1 2 3
------------------------------------
L2ARC device header
------------------------------------
    magic: 6504978260106102853
    version: 1
    pool_guid: 2855951775473507186
    flags: 1
    start_lbps[0]: 0
    start_lbps[1]: 0
    log_blk_ent: 0
    start: 4194816
    end: 1073217536
    evict: 4194816
    lb_asize_refcount: 0
    lb_count_refcount: 0
    trim_action_time: 0
    trim_state: 0

------------------------------------
L2ARC device log blocks
------------------------------------
No log blocks to read

[grahamperrin]

partitions

I'm a fool! Thanks.

root@mowa219-gjp4-8570p-freebsd:~ # zdb -l /dev/da0p1
------------------------------------
LABEL 0 
------------------------------------
    version: 5000
    state: 4
    guid: 7869384475889215193
    labels = 0 1 2 3 
------------------------------------
L2ARC device header
------------------------------------
    magic: 6504978260106102853
    version: 1
    pool_guid: 1913339710710793892
    flags: 1
    start_lbps[0]: 28458015744
    start_lbps[1]: 28433000448
    log_blk_ent: 1022
    start: 4194816
    end: 30943215616
    evict: 4194816
    lb_asize_refcount: 23027712
    lb_count_refcount: 1398
    trim_action_time: 0
    trim_state: 0

------------------------------------
L2ARC device log blocks
------------------------------------
log_blk_count:   1398 with valid cksum
                 0 with invalid cksum
log_blk_asize:   23027712

root@mowa219-gjp4-8570p-freebsd:~ # zdb -l /dev/da1p1
------------------------------------
LABEL 0 
------------------------------------
    version: 5000
    state: 4
    guid: 8248197705860927698
    labels = 0 1 2 3 
------------------------------------
L2ARC device header
------------------------------------
    magic: 6504978260106102853
    version: 1
    pool_guid: 1913339710710793892
    flags: 0
    start_lbps[0]: 12799508992
    start_lbps[1]: 12775627264
    log_blk_ent: 987
    start: 4194816
    end: 16565665792
    evict: 12820315136
    lb_asize_refcount: 11475968
    lb_count_refcount: 725
    trim_action_time: 0
    trim_state: 0

------------------------------------
L2ARC device log blocks
------------------------------------
log_blk_count:   725 with valid cksum
                 0 with invalid cksum
log_blk_asize:   11475968

root@mowa219-gjp4-8570p-freebsd:~ #