ZFS is a fantastic file system which revolutionizes data management. It has awesome features such as snapshots, dedup, the notion of pools and shares, effective software controlled raid and so much more.
However, there are some things to watch out for:
1) When doing snapshots make sure that your zfs pool versions are the same. Replicating data to pools of the same version is critical for many reasons. So be sure this is in place.
2) Scrub often. Disks will sometimes begin to fail and little or no error will be given. A scrub should make a failed disk easier to spot when doing a zpool status.
3) Don’t use raidz and not have a hotspare. Also make sure the hotspare is global. If you don’t want to have a hotspare (not recommended) then at least use raidz2 or raidz3. It is often recommended to use raidz2 or raidz3 AND have a hotspare.
4) ZFS is transaction based. Make sure transactions complete before proceeding to another transaction.
5) Try to use ZFS rather than UFS as your system pool. This feature is available in the recent releases of Solaris 10.
Following these simple precautions can save you a lot of headache when using zfs.