I have a NexentaStor-based NAS device on my home network. It has 10 x 500GB SATA Drives in a raidz2 configuration giving me approx 4TB of usable storage.
I don't have many users at home (basically, just me!) so I don't bother with any central authentication mechanism – I simply make sure that use I the same login (robin) across all servers, and on unix/linux servers I make sure the UID is the same (10000).
When a user is added to NexentaStor, it is allocated the next available UID beginning at 1001 (1000 is allocated to the admin user). For the robin login, I need this to be 10000.
Not a problem – simply drop to a bash shell on the NAS and use vipw to change the UID of the login.
The bit I *always* forget is that the CIFS server uses a different passwd file (/var/smb/smbpasswd) and it is necessary to change the UID in that file too.