imap scalability

[denz-wavenet]

hi!

Can u send us ur configuration for software and hardware for a case study.
How's redundancy is implemented. How r the backups implemented ?
We hope to use spampd with spammassasin, will this be a concern. For now
no antivirus scanning is thought of.

denzel.

----- Original Message -----
From: "Michael Loftis" <mloftis at wgops.com>
To: "denz-wavenet" <denz at wavenet.lk>; <info-cyrus at lists.andrew.cmu.edu>
Sent: Thursday, October 07, 2004 10:24 AM
Subject: Re: imap scalability


>
> --On Thursday, October 07, 2004 09:54 +0600 denz-wavenet <denz at wavenet.lk>
> wrote:
>
> > hi!
> >
> > Requirements:    host 10,0000 IMAP mailboxes
> >
> > Usual setup:  LDAP/SMTP-postfix/cyrus-iamp
>
> First -- do not run Cyrus over NFS, just don't do it.  Second, do not
share
> spool areas, cyrus does not handle this.
>
> If you've got compliant clients and servers then NFS *might* work.  You
> can't use a Linux NFS server, it doesn't qualify.  And I'm pretty sure the
> Linux NFS client is also in the doesn't' qualify area.  And performance
> will suck unless you go full Gig-E on a separate back-end network, and
even
> then, DAS or SAN will give you far more attractive results.
>
> Cyrus broaches the scaling issue with MURDER and using multiple back-ends
> but they DO NOT SHARE storage.  At all.
>
> That server may or may not be enough.  It really depends on what you mean
> by 10,000 users.  IF you mean 10k concurrent connections, no.  Also if it
> has IDE drives, even if you mean 10k mailboxes forget about it, IDE drives
> aren't going to keep up, you'll need about 3k random block io/second
> performance bare minimum using reiserfs and about 30-40G of mail data,
> other filesystems will have other patterns, ext2/3 will prolly see a LOT
> more read traffic due to the nature of it's inode layout.  Those numbers
> come from my live system where we've got around 12k mailboxes and prolly
> 3k-4k users, and about a million envelopes/day of mail volume coming in,
> with a LOT being dropped before that count by using DNS blacklists up
front.
>
> Scaling it also depends on your inbound mail, and mail flow, you going to
> be running AV scanning?  how about SpamAssassin?  going to allow the users
> to run scripts on their mail (i recommend not....) -- and by that I mean
> *not* SIEVE, like procmail or similar.
>
> At first glance, presumign that box has a beefy, and i mean beefy  -- like
> 7x10K RPM U160 SCSI drives on a real RAID subsystem, like a nice higher
end
> ICP Vortex card -- it should manage, it may get a little tight at times
but
> it should manage it alright.  as long as you dont' mean 10k concurrent
> sessions, then you're outside the league of a single box, talking about a
> decent sized load balanced front-end/back-end group of systems.
>

---
Cyrus Home Page: http://asg.web.cmu.edu/cyrus
Cyrus Wiki/FAQ: http://cyruswiki.andrew.cmu.edu
List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html