Creating a ZFS Pool With an Alternate Root Location
The most common reason for creating a pool at an alternate location is for use with removable media. In these circumstances, users typically want a single file system, and they want it to be mounted wherever they choose on the target system. When a pool is created by using the zpool create -R
command, the mount point of the root file system is automatically set to /
, which is the equivalent of the alternate root value.
In the following example, a pool called morpheus
is created with /mnt
as the alternate root location:
$ zpool create -R /mnt morpheus c0t0d0 $ zfs list morpheus NAME USED AVAIL REFER MOUNTPOINT morpheus 32.5K 33.5G 8K /mnt
Note the single file system, morpheus
, whose mount point is the alternate root location of the pool, /mnt
. The mount point that is stored on disk is /
and the full path to /mnt
is interpreted only in this initial context of the pool creation. This file system can then be exported and imported under an arbitrary alternate root location on a different system by using -R
alternate-root-value syntax.
$ zpool export morpheus $ zpool import morpheus cannot mount '/': directory is not empty $ zpool export morpheus $ zpool import -R /mnt morpheus $ zfs list morpheus NAME USED AVAIL REFER MOUNTPOINT morpheus 32.5K 33.5G 8K /mnt