Today with Gianluca i recovered a root password of a system with ZFS as volume manager.
The procedure is simple and composited by follow steps:
– boot from CDROM or in failsafe mode
– show the available pools to import
– identify and import the root pool ( in this case rpool )
zpool import -f -R /tmp/rpool rpool
– configure root dataset as legacy
zfs set mountpoint=legacy rpool/ROOT/solaris
– manually mount it
mount -F zfs rpool/ROOT/solaris /mnt
– change/reset the root password
for empty password also check the directive PermitEmptyPasswords in /etc/ssh/sshd_config
Remember to reset mountpoint property for root dataset !