[Dovecot] Configuration advices for a 50000 mailboxes server(s)

[Jan-Frode Myklebust]

On Tue, Apr 17, 2012 at 08:54:15AM -0300, Mauricio López Riffo wrote:
> 
>     Here we have approx. 200K users with 4000 concurrent connections
> (90% POP3 users)

How do you measure "concurrent" POP3 users?

> All servers in virtual environment Vmware,
> supermicro servers and Netapp Metrocluster storage solutions (nfs
> storage with 10G ethernet network)  POP3 sessions take betwen 40 and
> 300 milisecons at connect, auth and list.  All accounts lives in
> LDAP, CentOS 5 and exim like a mta relay.

Very interesting config. We're close to 1M accounts, GPFS cluster fs, LDAP,
RHEL5/6 and postfix + dovecot director for pop/imap/lmtp,  and moving from
maildir to mdbox. 

What mailbox-format are you using? Do you have a director, or accounts
sticky to a server some other way?

How's the NFS performance? I've always bean weary that NFS works
terribly with many small files (i.e. maildir)..

What does the metrocluster give you? Is it for disaster recovery on
second location, or do you have two active locations working against the
same filesystem?


  -jf