On 13/01/11 05:42, Jonathan Tripathy wrote:
On 13/01/11 05:36, Jaques Cochet wrote:
Hi
I'm working on a mail system design for an ISP that includes hosting
of multiple virtual domains managed by this ISP (300.000 mailbox). HA
and performance are both important concerns for the client, so I have
at least 2 of every server (webmail, pop3, imap, relay and smtp
(postfix)) for which i'm using either L4 or MX record load
balancing/HA.
I hate the idea of distributing mailboxes among servers and I'm trying
to go for a single mailstore that is accessible by POP3/IMAP servers
and delivery SMTP servers and I'm planning to use a SAN for this. The
basic idea is to share the mailstore between SMTP servers (clustered
storage using GFS maybe) and make the same mailstore available to
POP/IMAP server using NFS. Am I on the right track here?
Jaques
Jaques,
I asked these very questions yesterday on this list, so you may find
that info useful :) (Search for "Network Ideas" and look at recent
posts, as my inital posts had setup ideas that were too complicated)
Basically, what I'm going to do is have have 4 servers in total:
2 X "Mail Servers" which will run Postfix and Dovecot on the same box
2 X NFS Servers using DRBD and Linux-HA. The 2-server cluster will
export an NFS share to both mails servers
I'll also have additional incoming mails servers which will do
spam/virus filtering (no mail store hence no connection to NFS
cluster). Reading around, Postfix and Dovecot work very well in single
mail-store environments. I don't feel my requirements require me to
separate Dovecot and Postfix. I will use pfsense as a load balancer
though so both mail servers can be used at the same time.
I'm still debating between the above mentioned NFS/DRBD cluster and a
GlusterFS cluster. Reading around online, many people have had
performance issues with GlusterFS (As late as Sept 2010) so I'm not
sure this is a good idea.
This setup is just in planning, but its the latest idea I have.
Cheers
I should probably add that in my current idea, my database servers are
also separate in a DRBD/Linux-HA fashion. This means that both main mail
servers (which run postfix and dovecot), as well as the inbound mx
servers (which run postfix, spamassian and amavisd) can use it for
lookups. I havn't thought this far ahead yet, but I'm sure I can get my
inbound mx servers to look up the database to reject mail which the
whole system doesn't control, yet still use transport maps to send to
another server...
