I am using OpenSolaris 2008.05. If I do "zpool create -R /altroot mypool c0d3" then "zfs get mountpoint mypool" shows the value as "/altroot" rather then /altroot/mypool". If you then do "zpool export mypool" followed by "zpool import mypool", you get: cannot mount ''mypool'': No such file or directory because the root dataset mountpoint property is empty: -bash-3.2# zfs get mountpoint mypool NAME PROPERTY VALUE SOURCE mypool mountpoint local It seems rather than local and empty it should be default and /mypool. This message posted from opensolaris.org