[Dovecot] Some POP3 questions

[Brandon Lamb]

On Wed, May 6, 2009 at 5:25 AM, Kenneth Kalmer <kenneth.kalmer at gmail.com> wrote:
> On Tue, May 5, 2009 at 11:39 PM, Timo Sirainen <tss at iki.fi> wrote:
>
>> On Tue, 2009-05-05 at 23:32 +0200, Kenneth Kalmer wrote:
>> > >> * NFS server which is the same server that houses single Courier-IMAP
>> > >> installation (Gentoo, 3GB memory)
>> > >> * 2x Postfix instances delivering to NFS
>> > >>
>> > >
>> > > NFS may be problematic. Dovecot expects a perfectly working NFS setup,
>> > > which seems to be a bit rare to find. http://wiki.dovecot.org/NFS
>> > >
>> >
>> > Just for the record, dovecot will be access the mail directly on the
>> disks,
>> > it will be the LDA's on the postfix instances coming in over NFS. I'm
>> > reading the NFS again to make sure I understand the risks
>>
>> If the LDA is Dovecot deliver, it's the same problem since it also
>> updates index/control files that cause the problems. But if you're using
>> something else that does nothing but write the maildir files, then it's
>> fine.
>>
>
> I'm looking to use the Dovecot LDA so the caches are updated and the
> filenames are correct, to get good POP3 performance.
>
> I'm looking forward to giving Dovecot a go, but I'll rig up a staging
> environment first.
>
> Thanks for the encouraging responses everyone.
>
> Best
>
> --
> Kenneth Kalmer
> kenneth.kalmer at gmail.com
> http://opensourcery.co.za
> @kennethkalmer

I moved from a 4 gig nfs server with eight mailheads running exim as
lda, courier imap/pop3 (over nfs) to an 8 gig nfs server and moved to
dovecot imap/pop3 running directly on the nfs server and dropped to
four mailheads running exim with dovecot lda.

At first I tried to keep my imap/pop3 services running on the 4
mailheads but over nfs had major weird 500 load spikes randomly,
moving these to the nfs server solved all of that. The 4 mailheads
still deliver to maildir over nfs using dovecot as lda. I have been
pleasantly pleased. Our webmail app in our old setup used to take
10-30 seconds to load and now it is instantaneous. Some of it might be
from upgrading hardware, but I definitely had a HUGE noticeable
difference and you couldnt convince me to go back.

We did have about a week of sucktastic traffic and my support
department hating me because all our pop3 leave-messages-on-server
users had to redownload all their mail, but it was worth the headache.
Dovecot is just too sweet, with its performance and plugins to ever
have to even think about a choice between it or software X.

Just my $0.02