Large cyrus install surver

Paul M Fleming pfleming at
Wed Dec 3 11:04:24 EST 2003


sjh at wrote:
> Hi,
> I'm looking at setting up IMAP servers for a mid-sized (2,000-3,000)
> company with several sites around the world.  I've run Cyrus myself
> for years, and I'm very happy with it.   But, I'd like to collect some
> configurations from people with large scale installations (CMU does
> not count :).
> If people will email me their info, I'll make a little web page, and
> post the results here so that others can benefit as well.
> Send me:
> The version(s) of Cyrus you are running

	using cache layer/saslauthd to kerberosv5, native gssapi for admin

> The specs of the servers you have (cpu,mem,disk,os, etc)

all machines run Redhat 7.1 Kernel 2.4.18-17.7.x

4 backend mail stores (all identical)
	1 - PIII 1Ghz
	4 - 40GB U160 Drives
	Mylex 352 w/ Battery Backup
	4GB 	/var/imap
	88GB	/var/spool/imap

2 Front End Proxies (currently running custom code with plans to switch
to murder to get unified namespace)
	1 - PIII 866Mhz
	1 9G U160 drive

Front Ends also provide internal SMTP and LDAP. 4 External (outside
firewall) SMTP mail handlers and 3 KDCs for Kerberos. LDAP is mastered
on yet another machine. 

All SMTP handlers run Sendmail+Mimedefang+Spamassasin+McAfee and are
using LDAP routing for short-circuit delivery of inbound email. (virus
scanning really increases the load on SMTP relays btw)

WebMail is provided on a separate machine using IMP.

We have plans to use the Linux Virtual Server code to implement load
balancing across our LDAP/SMTP/IMAP frontends. Currently it's round
robin DNS ;(

> How many accounts on each server.


> The average and peak number of users on each server at a time

Average 600-800 concurrent users across the cluster. Fairly even
distribution across backends. We've seen login rates of 5-10/second.
Login load will depend on the nature of your clients (webmail is a
killer) and if your client is well behaved (Mozilla for example keeps an
open connection for long periods of time (sometimes days) but Netscape
New Mail Notify (not messenger) opens a new connection for each check. 

> The average and peak number of messages in a folder for your users
>  (go ahead and estimate here...)

No idea. currently using about 30GB of disk space total. Most users have
50Mb quotas. I have a few users with 1Gb mail stores.

> Are you using murder?  If so, describe your proxies and mupdate server.

We've tested murder and plan to deploy it -- a good authentication
backend makes murder easier to deploy.

> Any random thoughts you have.  Would you pick Cyrus if you were free
> to start over right now? etc.

We've been using Cyrus since 1.5.14 (late 1998). This is our second
generation of hardware but we deployed a cluster from the start. I've
posted several notes to the list over the years regarding our
performance tuning etc. (performance tuning was required to get the
level of stability we require) Someday I need to get all the information
up on a webpage. Cyrus has worked wonderfully in our environment.
Stability has been great (for example the first system of our 2nd
generation install has been up since it was installed - 340 days)

> What info about you (firstname, lastname, email, organization) is it ok
> for me to list with your info. (none at all is fine, and that's what I'll
> assume if you don't say otherwise)

Paul Fleming pfleming at Southern Illinois University School of
Medicine Springfield IL USA.

> email your info to sjh at
> Thanks,
> -Seth

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