====== Mount RAW Pool Image with ZFS on Linux ======

Suppose you have backed up a ZFS pool with ''dd'' so you want to get some data from ''rpool.img'' now. Look at [[disk-image-mount-partition]] for more ways to mount patitions.

===== Mounting =====

  - Mount image as loop device<code>
# losetup /dev/loop0 rpool.img
</code>
  - List partitions in loop<code>
# kpartx -l /dev/loop0
loop0p1 : 0 44019712 /dev/loop0 2048
loop0p9 : 0 16384 /dev/loop0 44021760
</code>
  - Create device mappings of partitions<code>
# kpartx -av /dev/loop0
add map loop0p1 (252:0): 0 44019712 linear 7:0 2048
add map loop0p9 (252:1): 0 16384 linear 7:0 44021760
</code>
  - Create mount point<code>
# mkdir /mnt/misa
</code>
  - Try import the ZFS pool, but it will definitely fail because 1) my ''rpool.img'' is readonly 2) ''rpool'' is already used on my system<code>
# zpool import -R /mnt/misa -d /dev/mapper
   pool: rpool
     id: 3090542417815288870
  state: ONLINE
 status: Some supported features are not enabled on the pool.
 action: The pool can be imported using its name or numeric identifier, though
        some features will not be available without an explicit 'zpool upgrade'.
 config:

        rpool       ONLINE
          loop0     ONLINE
</code>
  - With the id from previous result, we can import this pool with a new name ''misa''<code>
# zpool import -o readonly=on -f -d /dev/mapper 3090542417815288870 misa -R /mnt/misa
</code>
  - Done<code>
# zpool status
  pool: misa
 state: ONLINE
status: Some supported features are not enabled on the pool. The pool can
        still be used, but some features are unavailable.
action: Enable all features using 'zpool upgrade'. Once this is done,
        the pool may no longer be accessible by software that does not support
        the features. See zpool-features(5) for details.
  scan: none requested
config:

        NAME        STATE     READ WRITE CKSUM
        misa        ONLINE       0     0     0
          loop0     ONLINE       0     0     0

errors: No known data errors

# zpool list
NAME    SIZE  ALLOC   FREE  EXPANDSZ   FRAG    CAP  DEDUP  HEALTH  ALTROOT
misa   20.9G   716M  20.2G         -     0%     3%  1.00x  ONLINE  /mnt/misa

# zfs list misa -r
NAME                 USED  AVAIL  REFER  MOUNTPOINT
misa                 716M  19.5G    96K  /mnt/misa
misa/ROOT            533M  19.5G    96K  none
misa/ROOT/ubuntu     533M  19.5G   533M  /mnt/misa
misa/home            996K  19.5G    96K  /mnt/misa/home
misa/home/root       900K  19.5G   900K  /mnt/misa/root
misa/srv              96K  19.5G    96K  /mnt/misa/srv
misa/var             179M  19.5G    96K  /mnt/misa/var
misa/var/cache       174M  19.5G   174M  /mnt/misa/var/cache
misa/var/lib        3.81M  19.5G    96K  /mnt/misa/var/lib
misa/var/lib/mysql  3.72M  19.5G  3.72M  /mnt/misa/var/lib/mysql
misa/var/log        1.09M  19.5G  1.09M  /mnt/misa/var/log
misa/var/spool        96K  19.5G    96K  /mnt/misa/var/spool
misa/var/tmp         120K  19.5G   120K  /mnt/misa/var/tmp
</code>

===== Unmounting =====
  - Export the pool<code>
# zpool export misa
</code>
  - Disconnect the device map files using kpartx<code>
# kpartx -dv /dev/loop0
del devmap : loop0p9
del devmap : loop0p1
</code>
  - Unload loop device<code>
# losetup -d /dev/loop0
</code>

===== See Alsos =====
  * https://groups.google.com/forum/#!topic/zfs-fuse/s2njFgkOfhg
  * http://thegeekdiary.com/solaris-zfs-how-to-import-2-pools-that-have-the-same-names/
  * https://nfolamp.wordpress.com/2010/08/16/mounting-raw-image-files-and-kpartx/

{{tag>zfs zfs-on-linux disk-image kpartx loop}}