Storing incoming work dir on ramdisk

[Gerry Doris]

On Wed, 1 Jan 2003, Julian Field wrote:

> I've just done an experiment on my biggest server (thankyou Transtec!).
>
> I am ignoring incoming SMTP traffic load for now, as I have yet to find
> enough machines to feed it SMTP traffic at 1.5 million messages per day.
>
> Using disk-based directories for
>         mqueue.in
>         mqueue
>         MailScanner/incoming
>         using Exim
> I can process about 1.1 million messages per day, using Sophos,
> SpamAssassin and the default RBL lists.
>
> With tmpfs-based directories for
>         MailScanner/incoming
> this jumps to about 1.4 million messages per day, using the same settings.
> This is perfectly safe as the MailScanner/incoming directory is wiped at
> startup anyway, and no messages can be lost by power-outs.
>
> With tmpfs-based directories for
>         mqueue.in
>         mqueue
>         MailScanner/incoming
> this increases to about 1.5 million messages per day, using the same
> settings. This is not safe as the mqueue.in and.mqueue would be lost on
> power-outs.
>
> So if you have the RAM to throw at it, and plenty of CPU horse-power to
> make use of it, you can increase your message throughput by roughly 30% by
> moving the MailScanner/incoming directory onto a tmpfs filesystem held in RAM.
>
> But if you run out of RAM and start swapping a lot, the performance will
> drop quickly.
>
> Tests done on a Transtec 2600 Workgroup Server, 2 x 2.4GHz/Zeon with 2Gb
> RAM, 15000rpm SCSI disk, 15 child processes.
> --
> Julian Field
> www.MailScanner.info
> MailScanner thanks transtec Computers for their support

Those are pretty impressive numbers!  I noticed that you're testing with
Exim instead of sendmail.  Do you think there would be much difference if
you used sendmail?

BTW, do you think that Transtec would like to provide me with one of those
servers?  It would give my home mail server a little more "head room"!

--
Gerry

"The lyfe so short, the craft so long to learne"  Chaucer