Converting a non-HAST ZFS pool to a HAST pool

[Freddie Cash]

Has anyone looked into, attempted, or considered converting a non-HAST
ZFS pool configuration into a HAST one?  While the pool is live and
the server is in use.  Would it even be possible?

For example, would the following work (in a pool with a single raidz2
vdev, where the underlying GEOM provider is glabel)
  - zpool offline 1 drive  (pool is now running degraded)
  - configure hastd in master mode with a single provider using the
"offline" disk (hast metadata takes the place of glabel metadata)
  - zpool replace the offline drive using the /dev/hast/whatever provider
  - wait for ZFS to resilver the device
  - repeat for each disk in the vdev

Is it possible to change the hast configuration and reload hastd to
pick up new providers, without restarting it?  Without losing the
/dev/hast devices?  Or would it require a restart, which would cause
the /dev/hast/* devices to disappear, thus b0rking the pool?

Just wondering how hard it's going to be to move from our current
setup (backup server 1 rsync'd to backup server 2) to a HAST setup
(server 1 hast master with server 2 hast slave).

If the above won't work, then I guess I'll have to grab a third
storage box, configure that as a hast box, copy the data over, destroy
server 2, configure it as a hast box, and let them sync.

-- 
Freddie Cash
fjwcash at gmail.com