OVERVIEW:The new feature should be available in build 131.
Some practices in data centers are built around the use of a volume
manager's ability to clone data. An administrator will attach a set of
disks to mirror an existing configuration, wait for the resilver to
complete, and then physically detach and remove those disks to a new
Currently in zfs, the only way to achieve this is by using zpool offline
to disable a set of disks, zpool detach to permanently remove them after
they've been offlined, move the disks over to a new host, zpool
force-import of the moved disks, and then zpool detach the disks that were
This is cumbersome and prone to error, and even then the new pool
cannot be imported on the same host as the original.
Introduce a "zpool split" command. This will allow an administrator to
extract one disk from each mirrored top-level vdev and use them to create
a new pool with an exact copy of the data. The new pool can then be
imported on any machine that supports that pool's version.
See implementation details.