Transitioning From Oracle® Solaris 10 to Oracle Solaris 11.2

Exit Print View

Updated: December 2014
 
 

Displaying ZFS File System Information

After installing your system, review the ZFS storage pool and ZFS file system information.

Display ZFS storage pool information with the zpool status command.

Display ZFS file system information with the zfs list command.

See Reviewing the Initial ZFS BE After an Installation.

Resolving ZFS File System Space Reporting Issues

The zpool list and zfs list commands are more improved than the previous df and du commands for determining available pool and file system space. With the legacy commands, you cannot easily discern between pool and file system space, nor do the legacy commands account for space that is consumed by descendant file systems or snapshots.

For example, the following root pool (rpool) has 5.46 GB allocated and 68.5 GB free:

# zpool list rpool
NAME   SIZE  ALLOC   FREE  CAP  DEDUP  HEALTH  ALTROOT
rpool   74G  5.46G  68.5G   7%  1.00x  ONLINE  -

If you compare the pool space accounting with the file system space accounting by reviewing the USED columns of your individual file systems, you can see that the pool space is accounted for. For example:

# zfs list -r rpool
NAME                      USED  AVAIL  REFER  MOUNTPOINT
rpool                    5.41G  67.4G  74.5K  /rpool
rpool/ROOT               3.37G  67.4G    31K  legacy
rpool/ROOT/solaris       3.37G  67.4G  3.07G  /
rpool/ROOT/solaris/var    302M  67.4G   214M  /var
rpool/dump               1.01G  67.5G  1000M  -
rpool/export             97.5K  67.4G    32K  /rpool/export
rpool/export/home        65.5K  67.4G    32K  /rpool/export/home
rpool/export/home/admin  33.5K  67.4G  33.5K  /rpool/export/home/admin
rpool/swap               1.03G  67.5G  1.00G  -

Resolving ZFS Storage Pool Space Reporting Issues

The SIZE value that is reported by the zpool list command is generally the amount of physical disk space in the pool, but varies depending on the pool's redundancy level. The zfs list command lists the usable space that is available to file systems, which is disk space minus ZFS pool redundancy metadata overhead, if any. See the following examples for more information.

  • Non-redundant storage pool – Created with one 136-GB disk, the zpool list command reports SIZE and initial FREE values as 136 GB. The initial AVAIL space reported by the zfs list command is 134 GB, due to a small amount of pool metadata overhead. For example:

    # zpool create tank c0t6d0
    # zpool list tank
    NAME   SIZE  ALLOC   FREE    CAP  DEDUP  HEALTH  ALTROOT
    tank   136G  95.5K   136G     0%  1.00x  ONLINE  -
    # zfs list tank
    NAME   USED  AVAIL  REFER  MOUNTPOINT
    tank    72K   134G    21K  /tank
  • Mirrored storage pool– Created with two 136-GB disks, the zpool list command reports SIZE as 136 GB and initial FREE value as 136 GB. This reporting is referred to as the deflated space value. The initial AVAIL space reported by the zfs list command is 134 GB, due to a small amount of pool metadata overhead, as shown in the following example:

    # zpool create tank mirror c0t6d0 c0t7d0
    # zpool list tank
    NAME   SIZE  ALLOC   FREE    CAP  DEDUP  HEALTH  ALTROOT
    tank   136G  95.5K   136G     0%  1.00x  ONLINE  -
    # zfs list tank
    NAME   USED  AVAIL  REFER  MOUNTPOINT
    tank    72K   134G    21K  /tank
  • RAID-Z storage pool – Created with three 136-GB disks, the zpool list commands reports SIZE as 408 GB and initial FREE value as 408 GB. This reporting is referred to as the inflated disk space value, which includes redundancy overhead, such as parity information. The initial AVAIL space reported by the zfs list command is 133 GB, due to the pool redundancy overhead. The following example creates a RAIDZ-2 pool:

    # zpool create tank raidz2 c0t6d0 c0t7d0 c0t8d0
    # zpool list tank
    NAME   SIZE  ALLOC   FREE    CAP  DEDUP  HEALTH  ALTROOT
    tank   408G   286K   408G     0%  1.00x  ONLINE  -
    # zfs list tank
    NAME   USED  AVAIL  REFER  MOUNTPOINT
    tank  73.2K   133G  20.9K  /tank