On 03/23/10 07:43, Brian Candler wrote:
On Tue, Mar 23, 2010 at 05:42:02AM -0400, Charles Marcus wrote:
On 2010-03-22 9:31 PM, Stan Hoeppner wrote:
Dovecot has built in locking support for NFS storage.
But it has always been problematic, according to Timo.
Have you got any references on this, apart from http://wiki.dovecot.org/NFS ?
I'm looking at migrating a courier-imap installation (FreeBSD frontends,
Netapp backends, Maildir++) to dovecot. I'd be grateful of any known
pitfalls I should be looking out for.
I have done some small-scale testing and it looks fine. tcpdumping the NFS
traffic, I see that the FreeBSD frontend is sending "access" requests to
check that its local cache is not stale. In tests with mailboxes containing
100 messages and a web IMAP frontend (atmail.org), Dovecot was generating
about 1/4 of the total NFS traffic compared to courier-imap, because of how
Dovecot creates a cache file containing the message headers.
I see a link to http://www.freebsd.org/cgi/query-pr.cgi?pr=123755 in the NFS
wiki page. Does this problem affect only mbox over NFS, or maildir too?
I've not observed any problem with courier-imap, although courier-imap is
much dumber about caching, and also at the moment the majority of the
userbase are on POP3 anyway.
Regards,
Brian.
I've used:
mmap_disable: yes
mail_nfs_storage: yes
mail_nfs_index: yes
on FreeBSD 6/7/8 and dovecot with multiple servers accessing the same
mailboxes over NFS on a NetApp and it has worked fine since 1.0.16 or
so, I think. I use 1.1 now (haven't finished testing 1.2 and haven't
done much with 8.x). I have a load balancer in front and it sends IMAPS
connections or HTTPS connections (making local IMAP calls) to randomized
servers so even one person making 5 connections gets a speed benefit by
using more than one server.
If the NFS support had problems you could also use mail_location to keep
indexes local.
