[Mimedefang] Scaling MIMEDefang / SA on Solaris

[David F. Skoll]

On Wed, 16 Apr 2003, Phil Eschallier wrote:

> My problem is that with MD / SA deployed, the mail service falls flat on its
> face.

You absolutely *must* put /var/spool/MIMEDefang on a tmpfs on a busy
Solaris server.  If your /var/spool/MIMEDefang directory is
disk-based, it is probably the cause of your problems.

As a quick fix, do this:

	# Stop MIMEDefang
	rm -rf /var/spool/MIMEDefang
	mkdir /tmp/MIMEDefang
	chown defang /tmp/MIMEDefang
	chmod 700 /tmp/MIMEDefang
	ln -s /tmp/MIMEDefang /var/spool
	# Start MIMEDefang

You should notice a big improvement.

> Even during failure conditions, the server's load average doesn't exceed 4
> or 5 and is using only a bit of swap space.

Check how many processes are waiting for I/O.

> On larger sites, I find it key to run sendmail in daemon mode only (ie queue
> only) then use persistent queue runners to process mail.

This won't help, because SpamAssassin processing dominates Sendmail
processing by a large margin.  Also, if your problem is I/O contention,
running in queue-only mode won't help (and will in fact hurt.)

Regards,

David.