One of the attractions of ZFS pools is that they are prettyself-documenting. A ZFS pool automatically captures a great deal of thebasic information that you need to deal with it, such as the filesystemsit contains and NFS export settings. But this isn't quite all of theinformation that you need for long term management and for disasterrecovery, and in our new fileserver environment we've opted to duplicate some of the information outside of ZFS as well.

(Keeping track of filesystems, export permissions,

Our old SAN was set up in the traditional way: the SAN backend units didRAID-5 interally, and this RAID-5 space was carved up into LUNs and usedby the frontend fileservers. For natural reasons all of our fileservers wound up using LUNs from all of our SAN backends.This setup has low overhead , decent resilience,and decent performance.Our new fileservers are set up inan entirely different way, and among other things they use RAID-1instead of RAID-5. Although we were