[Gluster-users] Email storage backend for Sendmail, Maildir, and Courier-imap

[Keith Freedman]

At 05:16 AM 1/27/2009, Cory Meyer wrote:
>There was some talk of using GlusterFS for email storage last 
>November.  Is anyone else successfully using this in a production enviroment?

I use glusterfs 2.0rc1 on production web hosting environment, so this 
has email/imap/web/ftp

we don't really overload our servers so haven't really run into any 
performance issues.
There is still some performance issues related to small files, but 
this is mostly a fuse issue I belive.

We're going to be testing out mod_glusterfs in apache shortly to see 
if we get any noticeable web performance improvements, but on the 
mail things seem ok, although people using imap with >1500 messages 
in a folder sometimes experience long loading times, but this is 
mostly due to the imap server being stupid.  On the systems we've 
switched to dovecot from courier, this is less of an issue.  for POP 
it all seems to work just fine.

I'd definitely avoid courier not because of gluster just because it's 
terribly inefficient--it doesn't cache mail headers as far as I can 
tell and so it scans the filesystem every time someone establishes an 
imap connection--this is inefficient no matter what your filesystem.

for SMTP services we use exim instead of sendmail.  Sendmail is 
terribly inefficient.
Also it would depend how you configure it.. .presumably the 
cache/spool files would be on a local filesystem, and the delivered 
mail on a shared glusterfs.  if you want to spool into gluster you 
might be ok, but you'll possibly have multiple sendmail daemons 
fighting over the right to send a message and you'll likely have 
problems by having multiple machines attempting to send messages more 
frequently than the receiving servers want to hear from you.

Our email load also isn't too out of hand and the only thing that 
ever causes a problem is the anti-spam software (which processes 
messages outside of gluster, so that's not an issue).

hoep that helps.