Mapping ZFS pool to partition

Question

I have two ZFS mount points/a ZFS pool in a FreeBSD 12.0 server, that I can see with df:

$ df -h | grep zroot
zroot/vms      196G    657M    195G     0%    /vms
zroot          195G     19K    195G     0%    /zroot

How can I know in which partition it is located? Can I know a little more about it?

Answer 1

You can know more about your ZFS pool with several commands:

$zpool status
 pool: zroot
 state: ONLINE
  scan: none requested
config:

    NAME        STATE     READ WRITE CKSUM
    zroot       ONLINE       0     0     0
      nvd0p4    ONLINE       0     0     0

errors: No known data errors

As you can see, a ZFS pool zroot was created in the nvd0p4 partition.

You can also get a few more glimpses about the characteristics of the pool with the command zpool list:

$zpool list
NAME    SIZE  ALLOC   FREE  EXPANDSZ   FRAG    CAP  DEDUP  HEALTH  ALTROOT
zroot   202G   657M   201G         -     0%     0%  1.00x  ONLINE  -

As root, you can also see the history of the ZFS pool usage:

$sudo zpool history
History for 'zroot':
2017-01-16.22:00:43 zpool create zroot /dev/nvd0p4
2017-01-16.22:48:59 zfs create -V16G -o volmode=dev zroot/linuxdisk0
2017-01-16.22:49:33 zfs destroy zroot/linuxdisk0
2017-01-17.20:59:04 zfs create -o mountpoint=/vms zroot/vms
2017-01-17.21:21:35 zfs create zroot/vms/testvm
2017-01-17.21:21:40 zfs create -sV 16G -o volmode=dev zroot/vms/testvm/disk0
2017-01-17.21:23:41 zfs destroy -rf zroot/vms/testvm
2017-01-30.22:24:59 zfs create zroot/vms/testvm
2017-01-30.22:25:04 zfs create -sV 16G -o volmode=dev zroot/vms/testvm/disk0
2017-01-30.22:35:15 zfs destroy -rf zroot/vms/testvm   

You can also list the mounted ZFS filesystems:

$ zfs mount
zroot/vms                       /vms
zroot                           /zroot

ZFS has also support for snapshots, jails, and much more. See man zfs and man zpool for more details.

See also ZFS Tutorials : Creating ZFS pools and file systems