NFS and MIX ?

I have read much of the imapd docs, and some of the email threads on this 
list, so yes, I've seen "NFS is bad".

However .. we bought a fancy expandable storage system from Sun which has 
a native ZFS filesystem exported as NFS, CIFS, HTTP, iSCSI.
We'd like to use it for email from a Linux client (i.e. the mailserver 
uses it for user mail directories), as our in-chassis array is full.
We tried Linux XFS over iSCSI on RHEL4, which crashed and burned quickly.
Then we used Linux ext3 over iSCSI, which seemed OK for a couple of weeks 
but then bombed. It's possible the iSCSI support in RHEL5 is better; we have other 
machines running with that, but not doing mail with that kind of load 
pattern.

If we used NFS, then it might (?) be more reliable, and the device could 
use snapshotting for backups, which is built into its management 
interface.

What are the chances of this working ? There would be no sharing of
files with any other NFS clients, just the one disk mount.

How about other imap servers such as Dovecot ? Apparently it alleges 
it's NFS-safe, but one the posts here casts doubt on that.