Hi list,

I've been perusing the list archives, but I couldn't find a recent, definitive answer to what I'd like to know. I'm looking to set up a new batch of servers to migrate ~160,000 accounts, spread across several domains, onto (from CommuniGate). Last year I worked with the earlier beta/RC versions of Dovecot, so I'm generally familiar with the setup required. However, a lot of development has been done since I was last dealing with it.

So, what I'd like to end up with is a load balanced group of servers providing pop and imap access with quota support using an NFS filesystem. We have a new Netapp device (forget the actual model) that can do SAN/iSCSI/NFS. We tried using various clustered filesystems previously, but the performance/stability issues were a nightmare, so I've fallen back to NFS (or perhaps SAN if users can't hit any server in the group).

So, what does my dovecot setup need to be? I've seen some people say they disable indexing in the LDA, but allow pop/imap to index. Some say the attribute cache needs to be disabled, which I'd think would be worse than just disabling indexes. Some say indexes should be kept on local disk (dedicated server for users), and others seem to report problems even when doing so. Is there a general consensus?

I was also wondering if dovecot's sanity checking on the indexes would allow each server in a balanced group to keep indexes on local disk (so if the maildir has changed on another server, dovecot rebuilds it). If so, does that take away all performance gains from having indexes at all?

Thanks for any info you all can provide.