This diskfailure should not panic a system, but just disconnect disk from ZFS

[Willem Jan Withagen]

Hi,

Found my system rebooted this morning:

Jun 20 05:28:33 zfs kernel: sonewconn: pcb 0xfffff8011b6da498: Listen
queue overflow: 8 already in queue awaiting acceptance (48 occurrences)
Jun 20 05:28:33 zfs kernel: panic: I/O to pool 'zfsraid' appears to be
hung on vdev guid 18180224580327100979 at '/dev/da0'.
Jun 20 05:28:33 zfs kernel: cpuid = 0
Jun 20 05:28:33 zfs kernel: Uptime: 8d9h7m9s
Jun 20 05:28:33 zfs kernel: Dumping 6445 out of 8174
MB:..1%..11%..21%..31%..41%..51%..61%..71%..81%..91%

Which leads me to believe that /dev/da0 went out on vacation, leaving
ZFS into trouble.... But the array is:
----
NAME               SIZE  ALLOC   FREE  EXPANDSZ   FRAG    CAP  DEDUP
zfsraid           32.5T  13.3T  19.2T         -     7%    41%  1.00x
ONLINE  -
  raidz2          16.2T  6.67T  9.58T         -     8%    41%
    da0               -      -      -         -      -      -
    da1               -      -      -         -      -      -
    da2               -      -      -         -      -      -
    da3               -      -      -         -      -      -
    da4               -      -      -         -      -      -
    da5               -      -      -         -      -      -
  raidz2          16.2T  6.67T  9.58T         -     7%    41%
    da6               -      -      -         -      -      -
    da7               -      -      -         -      -      -
    ada4              -      -      -         -      -      -
    ada5              -      -      -         -      -      -
    ada6              -      -      -         -      -      -
    ada7              -      -      -         -      -      -
  mirror           504M  1.73M   502M         -    39%     0%
    gpt/log0          -      -      -         -      -      -
    gpt/log1          -      -      -         -      -      -
cache                 -      -      -      -      -      -
  gpt/raidcache0   109G  1.34G   107G         -     0%     1%
  gpt/raidcache1   109G   787M   108G         -     0%     0%
----

And thus I'd would have expected that ZFS would disconnect /dev/da0 and
then switch to DEGRADED state and continue, letting the operator fix the
broken disk.
Instead it chooses to panic, which is not a nice thing to do. :)

Or do I have to high hopes of ZFS?

Next question to answer is why this WD RED on:

arcmsr0 at pci0:7:14:0:    class=0x010400 card=0x112017d3 chip=0x112017d3
rev=0x00 hdr=0x00
    vendor     = 'Areca Technology Corp.'
    device     = 'ARC-1120 8-Port PCI-X to SATA RAID Controller'
    class      = mass storage
    subclass   = RAID

got hung, and nothing for this shows in SMART....


Thanx,
--WjW

(If needed vmcore available)