Provided by: zfsutils-linux_2.1.5-1ubuntu6_amd64 bug


     zfs-upgrade — manage on-disk version of ZFS filesystems


     zfs upgrade
     zfs upgrade -v
     zfs upgrade [-r] [-V version] -a|filesystem


     zfs upgrade
       Displays a list of file systems that are not the most recent version.

     zfs upgrade -v
       Displays a list of currently supported file system versions.

     zfs upgrade [-r] [-V version] -a|filesystem
       Upgrades file systems to a new on-disk version.  Once this is done, the file systems will
       no longer be accessible on systems running older versions of ZFS.  zfs send streams
       generated from new snapshots of these file systems cannot be accessed on systems running
       older versions of ZFS.

       In general, the file system version is independent of the pool version.  See
       zpool-features(7) for information on features of ZFS storage pools.

       In some cases, the file system version and the pool version are interrelated and the pool
       version must be upgraded before the file system version can be upgraded.

       -V version  Upgrade to version.  If not specified, upgrade to the most recent version.
                   This option can only be used to increase the version number, and only up to
                   the most recent version supported by this version of ZFS.

       -a          Upgrade all file systems on all imported pools.

       filesystem  Upgrade the specified file system.

       -r          Upgrade the specified file system and all descendent file systems.