OPNsense troubleshooting

OPNsense doesn't boot due to possible disk failure¶

zio_read error: 5
zfs: i/o error all block copies available
zfs can't read mos of pool zroot 
can't find /boot/zfsloader 
can't find /boot/loader 
can't find /boot/kernel/kernel

Download the OPNsense vga image, write to usb and boot from it¶

{{< ref "docs/opnsense/install-opnsense.md#download-the-image-and-write-to-usb-device" >}}

zfs¶

Initially should be no pools available before importing

zpool status
no pools available

List the pools available

zpool import
   pool: zroot
     id: 15907498437198183935
  state: ONLINE
 action: The pool can be imported using its name or numeric identifier.
 config:

    zroot       ONLINE
      ada0p4    ONLINE

Check gpart shows the disk

gpart show # get a list of disks

gpart show ada0
=>        40  7814037088  ada0  GPT  (3.6T)
          40      532480     1  efi  (260M)
      532520        1024     2  freebsd-boot  (512K)
      533544         984        - free -  (492K)
      534528    16777216     3  freebsd-swap  (8.0G)
    17311744  7796723712     4  freebsd-zfs  (3.6T)
  7814035456        1672        - free -  (836K)

Import the pool listed above read-only

zpool import -o readonly=on -f zroot
cannot mount '/zroot': failed to create mountpoint: Read-only file system
Import was successful, but unable to mount some datasets

Listing pools should now show the pool

zpool list
NAME    SIZE  ALLOC   FREE  CKPOINT  EXPANDSZ   FRAG    CAP  DEDUP    HEALTH  ALTROOT
zroot  3.62T      0  3.62T        -         -     0%     0%  1.00x    ONLINE  -

List available datasets

zfs list -r zroot
NAME                 USED  AVAIL  REFER  MOUNTPOINT
zroot               3.37G  3.51T    96K  /zroot
zroot/ROOT          1.18G  3.51T    96K  none
zroot/ROOT/default  1.18G  3.51T  1.18G  /
zroot/home           144K  3.51T   144K  /home
zroot/tmp           1.12M  3.51T  1.12M  /tmp
zroot/usr           1.71G  3.51T    96K  /usr
zroot/usr/ports      892M  3.51T   892M  /usr/ports
zroot/usr/src        858M  3.51T   858M  /usr/src
zroot/var            465M  3.51T    96K  /var
zroot/var/audit       96K  3.51T    96K  /var/audit
zroot/var/crash      132K  3.51T   132K  /var/crash
zroot/var/log        464M  3.51T   464M  /var/log
zroot/var/mail        96K  3.51T    96K  /var/mail
zroot/var/tmp        104K  3.51T   104K  /var/tmp

mkdir /tmp/zroot
ls -la /tmp/zroot/
total 9
drwxr-xr-x  2 root wheel  2 Nov 12 18:04 .
drwxrwxrwt  6 root wheel 21 Nov 12 19:42 ..

At this point in the process I found out that the ZFS pool metadata on the disk is probably completely unreadable and I re-installed and restored from backup.