technology, amateur radio, scouting and me

Upgrading the disk space in my ZFS-based servers – pt 2

See here for part 1

On Eridani

Once the initial send/recv had completed, I did another snapshot and sent the incremental data just in case anything had changed.

root@eridani ~ $ zfs snapshot -r zones@txfr2
root@eridani ~ $ zfs send -R -i txfr zones@txfr2 | pv | zfs recv tempzone

Lastly, I promoted the incremental snapshot to be the current version of tempzone

root@eridani ~ $ zfs rollback tempzone@txfr2

As a final (paranoid) check, I ran a dummy rsync task to check if /zones was the same as /tempzone

root@eridani ~ $ rsync -avn /zones/ /tempzone/ | less
sending incremental file list
global/cores/

sent 765011152 bytes  received 2764561 bytes  486087.82 bytes/sec
total size is 3454738169591  speedup is 4499.67 (DRY RUN)

Nothing had changed, so I could now swap the pools over

root@eridani ~ $ zpool export tempzone

GOTCHA!

I couldn’t export the root zones pool at this point because it had mounted filesystems that were in use by the running system. To get further I had to reboot the system into restore/recovery mode.

In this mode, no pools are imported, so I could execute the following commands

zpool status - to confirm that no pools were mounted
zpool import - to see what pools were available
zpool import -NR /t1 tempzone zones - -NR to avoid any datasets being mounted and use an alternate mount point
zpool import -NR /t2  zones oldzones
zpool export oldzones
zpool export zones
reboot

I was still getting errors even though the pools had been renamed. The problem turned out to be that when SmartOS boots, it seems to mount the pools in alphabetical order.

Probably more likely that SmartOS scans the disks in alphabetical order

Thus, oldzones was mounted before zones and it’s datasets were grabbing the mount points.
Rather than laboriously change the mountpoint property on all the datasets, I simply disconnected the disk.

Once I had completed this, eridani booted using the new pool.

root@eridani ~ $ 
root@eridani ~ $ zpool status
  pool: zones
 state: ONLINE
  scan: none requested
config:

    NAME        STATE     READ WRITE CKSUM
    zones       ONLINE       0     0     0
      raidz1-0  ONLINE       0     0     0
        c2d1    ONLINE       0     0     0
        c3d0    ONLINE       0     0     0
        c3d1    ONLINE       0     0     0

errors: No known data errors
root@eridani ~ $ zfs list
NAME                                                                  USED  AVAIL  REFER  MOUNTPOINT
zones                                                                2.52T  2.73T   318K  /zones
zones/archive                                                        29.3K  2.73T  29.3K  none
zones/backup                                                         2.50T  2.73T  29.3K  /zones/backup
zones/backup/deneb                                                   2.50T  2.73T  29.3K  /zones/backup/deneb
zones/backup/deneb/zones                                             2.50T  2.73T   324K  /zones/backup/deneb/zones
...
zones/config                                                         55.9K  2.73T  36.0K  legacy
zones/cores                                                          58.6K  2.73T  29.3K  none
zones/cores/global                                                   29.3K  10.0G  29.3K  /zones/global/cores
zones/dump                                                           1023M  2.73T  1023M  -
zones/opt                                                             423M  2.73T   422M  legacy
zones/swap                                                           17.9G  2.74T  1.44G  -
zones/usbkey                                                         38.6K  2.73T  38.6K  legacy
zones/var                                                            7.08M  2.73T  5.42M  legacy
root@eridani ~ $ zfs mount
zones                           /zones
zones/backup                    /zones/backup
zones/backup/deneb              /zones/backup/deneb
zones/backup/deneb/zones        /zones/backup/deneb/zones
...
zones/backup/deneb/zones/usbkey  /zones/backup/deneb/zones/usbkey
zones/backup/deneb/zones/var    /zones/backup/deneb/zones/var
zones/cores/global              /zones/global/cores
zones/var                       /var
zones/config                    /etc/zones
zones/opt                       /opt
zones/usbkey                    /usbkey
root@eridani ~ $ 

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