On Mon, Feb 09, 2004 at 06:18:26AM +0800, Maren S. Leizaola wrote:
On Sun, 8 Feb 2004, Kelsey Cummings wrote:
On Sat, Feb 07, 2004 at 01:08:31AM -0500, Errol Casey wrote:
I've read various documents on mail servers and Netapps and other NFS servers etc, . but thought I would ask the question.
What MTA (sendmail, postfix, qmail, exim, etc.) have admins chosen to run and their reasoning if they would be open to sharing their feelings.
The MTA is mostly irrelevant -- you wouldn't put your queues on a netapp would you?
I would! In fact that would be my number one reason for using a NetApp if I was running marketing mailing lists or carry high volumes of email.
When using postfix and queueing email through port 25 on a single scsi 160 disk you can get only 11 messages queued per second. Why? It when queing email the biggest bottle neck is how fast the drive can seek as it is very intensive on seeks. That is at least with the standard postfix (safe writing) configuration.
It seems to me that your better off using locally attached raid for mailqueues unless you really want the ability to share them between servers. We're using 3wares and raptors which are considerably more affordable - and faster - than using netapps, for mail queues. This also allows you to take specific measures in tuning your filesystem and raid for the task at hand.
It's all about your LDA and POP/IMAP servers. You'll must run Maildir, or you'll be in for trouble. You'll want to run Maildir++. Using a hacked courier server, our pop servers can login and return a UIDL for a box with 50k messages in it in under a second. We also hacked procmail to do Maildir++.
That is pretty cool however after you load 50K messages in under a second you will find that bandwidth and the speed at which the client can process the headers is the biggest bottleneck. Still it is not a bad idea to be able to load in 1 second.
It is cool. Of course bandwidth to the client is the real bottleneck but this provides clients with very low latency pop sessions -- no waiting for the server to build the UIDL, which on similar mbox or even Maildir stores could take minutes to provide -- leaving messages on the server is not a problem. Customer's don't stare at their client's waiting for it to finish 'authentication'.