zfs mirrorの取り換え

freebsd

別段dmesgにエラー出すこともなく何となく動き続けてたのだけど、どうも動きがもっさりしてきたので、昨晩zpool scrubしといたら、エラー吐きまくってた。というわけで、予備のHDDと交換。
まったく同じWD30EZRXを買ってたので、さくっと入れ替え。メモ。

取り換え前

# zpool status
  pool: ztank
 state: ONLINE
status: scrub canceled on Mon Sep 15 20:41:02 2014
config:

        NAME        STATE     READ WRITE CKSUM
        ztank       ONLINE       0     0     0
          mirror-0  ONLINE       0     0     0
            ada1p3  ONLINE       0     0     0
            ada0p3  ONLINE       0     0     0

errors: No known data errors

取り外し

# zpool detach ztank ada0p3
# zpool status
  pool: ztank
 state: ONLINE
status: scrub canceled on Mon Sep 15 20:41:02 2014
config:

        NAME        STATE     READ WRITE CKSUM
        ztank       ONLINE       0     0     0
          ada1p3    ONLINE       0     0     0

errors: No known data errors
#  gpart show ada0
=>        34  5860533101  ada0  GPT  (2.7T)
          34           6        - free -  (3.0k)
          40         128     1  freebsd-boot  (64k)
         168     2097152     2  freebsd-swap  (1.0G)
     2097320  5858435808     3  freebsd-zfs  (2.7T)
  5860533128           7        - free -  (3.5k)

シャットダウンして、ada0を新しいHDDに差し替える。
SingleUserModeでリブートして、いつもの作業前のお約束。

# mount -u /
# zfs mount -o ro ztank/usr
# zfs mount ztank/var
# zfs mount ztank/var/empty
# zfs mount ztank/tmp
# /etc/rc.d/adjkerntz start

HDDが同じなので、元のgpart通りに切ればよし、その後で、mirrorに追加する。

# gpart add -b 40 -s 128 -t freebsd-boot ada0
ada0p1 added
# gpart add -b 168 -s 2097152 -t freebsd-swap ada0
ada0p2 added
# gpart add -b 2097320 -t freebsd-zfs ada0
ada0p3 added
# gpart bootcode -b /boot/pmbr -p /boot/gptzfsboot -t 1 ada0
# zpool attach ztank ada1p3 ada0p3
Make sure to wait until resilver is done before rebooting.

If you boot from pool 'ztank', you may need to update
boot code on newly attached disk 'ada0p3'.

Assuming you use GPT partitioning and 'da0' is your new boot disk
you may use the following command:

        gpart bootcode -b /boot/pmbr -p /boot/gptzfsboot -t 1 da0

しばらくたった後。

# zpool status
  pool: ztank
 state: ONLINE
status: One or more devices is currently being resilvered.  The pool will
        continue to function, possibly in a degraded state.
action: Wait for the resilver to complete.
  scan: resilver in progress since Mon Sep 15 12:21:14 2014
        403G scanned out of 2.64T at 71/s, (scan is slow, no estimated time)
        403G resilvered, 14.93% done
config:

        NAME        STATE     READ WRITE CKSUM
        ztank       ONLINE       0     0     0
          mirror-0  ONLINE       0     0     0
            ada1p3  ONLINE       0     0     0
            ada0p3  ONLINE       0     0     0  (resilvering)

errors: No known data errors