Upgrading the ZFS filesystem and zpool versions is a one-way operation. Once upgraded, the versions cannot be downgraded. This will prevent booting from older boot environments if support for the upgraded zpool/filesystem version is not available within those boot environments. Thus it is important to chcek the zpool version before the upgrade.
The current zpool version can be checked with either of the following commands:
# zpool upgrade # zpool get version [zpool name]
For example:
# zpool upgrade This system is currently running ZFS pool version 29. All pools are formatted using this version.
# zpool get version datapool NAME PROPERTY VALUE SOURCE datapool version 29 default
The current ZFS filesystem version can be checked with:
# zfs upgrade # zfs get version [ZFS filesystem name]
For example:
# zfs upgrade This system is currently running ZFS filesystem version 5. All filesystems are formatted with the current version.
# zfs get version datapool/datafs NAME PROPERTY VALUE SOURCE datapool/datafs version 5 -
A list of available versions can be obtained using:
# zpool upgrade -v This system is currently running ZFS pool version 29. The following versions are supported: VER DESCRIPTION --- -------------------------------------------------------- 1 Initial ZFS version 2 Ditto blocks (replicated metadata) 3 Hot spares and double parity RAID-Z 4 zpool history 5 Compression using the gzip algorithm 6 bootfs pool property 7 Separate intent log devices 8 Delegated administration 9 refquota and refreservation properties 10 Cache devices 11 Improved scrub performance 12 Snapshot properties 13 snapused property 14 passthrough-x aclinherit 15 user/group space accounting 16 stmf property support 17 Triple-parity RAID-Z 18 Snapshot user holds 19 Log device removal 20 Compression using zle (zero-length encoding) 21 Reserved 22 Received properties 23 Slim ZIL 24 System attributes 25 Improved scrub stats 26 Improved snapshot deletion performance 27 Improved snapshot creation performance 28 Multiple vdev replacements 29 RAID-Z/mirror hybrid allocator For more information on a particular version, including supported releases, see the ZFS Administration Guide.
# zfs upgrade -v The following filesystem versions are supported: VER DESCRIPTION --- -------------------------------------------------------- 1 Initial ZFS filesystem version 2 Enhanced directory entries 3 Case insensitive and File system unique identifier (FUID) 4 userquota, groupquota properties 5 System attributes For more information on a particular version, including supported releases, see the ZFS Administration Guide.