I use Solaris 10 on SPARC. I have /usr legacy mounted on a zpool 'usr-pool'.

I now need to move some of the devices in usr-pool to another zpool which is running out of room.

What is the safest way for me to do this? I already know that (since my zpool is not mirrored) I need to destroy and recreate the zpool. I know how to backup and restore a zfs snapshot. However... I'm stumped on how to unmount usr-pool without losing access to the commands I need on /usr to complete the backup/restore.

Cursory research indicated that I should boot to OpenBoot (init 0) and then 'boot cdrom -s'. I did this but none of the zpools are accessible on that runlevel.

I also read I could just copy /usr to another location, symlink /usr to that location, then do my backup/restore. Is that safe to do?

I would appreciate some guidance.

S.