[rhn-users] Server goes to "sleep". E-mail, web won't respond.

[Rob Myroon]

Hi,

I have a problem that has me stumped and I don't know where to look.

I am running OpenExchange and the server has periods where it will not
respond to an e-mail client like Thunderbird or Netscape. Also,
sometimes our website and webmail will not respond either. And then a
bit later, sometimes 5 minutes, sometimes longer, the server will wake
up and everything will start working normally.

I suspect it has something to do with OpenExchange but I am not positive.

OpenExchange uses the following

- Redhat Application Server
- postfix
- cyrus
- openldap
- tomcat
- postgresql
- apache

When the e-mail goes to sleep postfix will still accept incoming e-mails
(I can see them in the user directorys). This makes me think that
postfix is not the problem. Maybe it is cyrus (the pop/imap server)? But
why doesn't the webmail respond?

Maybe it is my server? It is a Dell SC1420 (3 GHz Xeon). OS is RHEL4 ES.

I can't find anything in any log files.

I also run samba, plone, and recently openvpn. Samba works fine even
when the e-mail/imap/http servers appear to go to sleep.

I recently added 1 more gig of ram so the server now has 2 gigs. No swap
is used since I added the 2nd gig. The cpu is almost always 99.x% idle.
Memory used when the server is rebooted starts at around 750 MB and
creeps up to about 1.1 GB by the next day.

I haven't used ethereal but it's the only thing I can think of trying.
Does anyone have any suggestions before I get forced to switch to ms
products? Thanks.

Rob