Re: Sugesstions building a rather big mail system.
Im building one for about 120,000 little university brats and their
teachers....
Ive already designed it and decided exactly that way... postfix, ldap,
courier, san, apache, squirrelmail.
BUT, we decided to split by "breed".
For example, we will use two Dual-P4Xeon 2Gb for the IMAP/POP, same for
the SMTP (same kind of server, but another two servers).
Then, the apache (which i am most afraid about) are the ones that spell
trouble BIGTIME. This is because php/sm will prove to be the most
resource intensive application in the farm (SMTP is simple, IMAP is
simple). So we give it three of the same boxen and its own dual pair of
LVS.
THen, the backend, this will be two failover enabled boxes with postgres
and openldap. They will be quad xeon 6GB ram.
All of that, goes to the SAN. The local storage in each server should
respond mostly to services cache necesities (a php cache for the apaches
perhaps).
Let me know what you guys think.... this whole farm is about twelve
servers, 4 LVS (a pair for IMAP and SMTP and its own pair for apache), 2
IMAP/POP, 2 SMTP, 3 APACHE, 2 (bigger) Backend -> SQL/LDAP and the SAN.
El lun, 06-10-2003 a las 09:51, Theodore Knab escribió:
> How many servers do you have running this ?
>
> >I have been approached about building a rather big mail system handling
> >500.0000 existing accounts (running today on a windows based product (ick))
> >with a growth about 50.000 new accounts per year.
> >The services needed is: smtp, pop3, imap4.
>
> >I have used LVS for about 3y with good results for 30.000 accounts.
> >But this is certainly a bigger project. Should I go for alteon or any other
> >closed product or stick with LVS?
>
> >Is there anyone on the list running such a system or have some comments about
> >building such a system? (I do prefer to use OS/FS Software)
>
> Sounds like you have a fun project.
>
> I re-did a campus mail-system a few years ago here, and I
> still manage it. It is much smaller [and under powered] with only
> 3000+ users, but I have learned a lot running an Open Source mail system
> based on:
> Postfix [with LDAP] MTA
> Courier [with LDAP] IMAP
> OpenLDAP [ mail routing and accounts]
> Squirrel Mail [ Web-mail]
>
> In running my own open source mail system for a 1.5+ years,
> I would probably do a few things differently if
> I had the opportunity to setup one again. More specifically, I would
> probably use the SUN one product rather than Open Source. Although I do
> not know anything about SUN one [or IPlanet], it appears from this side
> of the fence to have simpler administrative tools and it has training.
> With open source you [alone] are the subject matter expert unless you
> find someone that is interested in learning and someone that you can
> trust.
>
> Since you are familiar with LVS, you should have no problem setting 2
> [redundant] LVS systems up. You could balance the load between 10-20
> IMAP servers.
>
> You might also be able to use the same 2 LVS systems to balance your
> load between the Web-mail servers.
>
> <Crude Diagram>
>
> [Firewall]
> |
> |
> |
> [LVS1]----[LVS2]
> | |
> [Fiber Only Switch]
> |
> Estimated Minimums needed for 500,000+ Email Users
> --------------------------
> 10 IMAP servers [Courier IMAP 1 [Dual Xeon 1GHz] server /200 active users]
> w/ XFS filesystem and Debian Stable
>
> 20 Webmail Servers [Squirrel-mail 1 [Dual Xeon 1Ghz] server /100 active users]
> w/ XFS filesystem and Debian Stable
>
> 2 Databases Servers for authentication either [Mysql or OpenLDAP]
> w/ XFS filesystem and Debian Stable
>
> 2-4 MX Gateways running either Exim or Postfix MTA and SPAMD with
> w/ XFS filesystem and Debian Stable
> Amivisd
> 2 [Fiber Channel] SAN Volumes for [MAIL storage] redundancy.
> </Crude Diagram>
>
> --
> ------------------------------------------
> Ted Knab
> Chester, MD 21619
>
> ------------------------------------------
> 940216d6021602a41607166696c656c202778696368602d65616e637
> 02940226c696e646c69702c6f667560256675627478696e67602a416
> 0716e6563756e2a0
>
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