----- Original Message -----
From: "Wietse Venema" <[email protected]>
To: "Brandon Hilkert" <[email protected]>
Cc: <[email protected]>
Sent: Friday, March 20, 2009 11:30 AM
Subject: Re: Performance tuning
Brandon Hilkert:
Sorry if this is a stupid question, but how do I go about this. I tried:
mkdir /ram
mount -t ramfs none /ram
and when I send a mail, postfix says there's not enough space in the
queue.
Should I be doing it a different way?
Postfix requires that the amount of space is several times larger
than the message size limit
http://www.postfix.org/postconf.5.html#queue_minfree
http://www.postfix.org/postconf.5.html#message_size_limit
I was able to get it to mount to tmpfs and it showed no change in
performance, so that would theoretcially rule out any existing disk issue
right?
I also put the queue directory back on an ext3 partition and the rates
went
up by about a factor of two.
Which confirms that XFS is not the best choice to quickly create/delete
of lots of little files.
Also, by default the syslog messages were already set with
" -/var/log/mail.log". I disabled mail logging all together and found no
change in rates.
Good.
My disk is writing about 3 MB/s which should be well within it's range. I
would hope even larger, but I would like to work out the ramfs and test
for
sure.
Bitrates are completely irrelevant.
what is best to look out and compare?
Email is about creating and deleting lots of tiny files.
You need to forget everything you learned about web servers, as it
does not apply to email.
Wietse
