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Re: Sendmail or Qmail ? ..

> On Sun, 7 Sep 2003 02:19, Cameron L. Spitzer wrote:
> > I've been running Qmail since '98.  It's got a bottleneck
> > in disk writes, but aside from that it's fast.
> > (Anybody tried running the queue in a ramdisk?
> Running the queue on a ramdisk would kill reliability.

Indeed, been there done that. In fact, something I wrote a long while ago
about how to increase Qmail's performance greatly (splitting the queues
onto two different hard disks/spindles) made it into Debian Weekly news or
something. Search Google or the mail list archives for more info on that.

And if it is going to be primarily an outgoing mail server, putting it on
a Ramdisk makes it deadly fast, but as Russell said... would lose those
emails if it suddenly crashed.

> Using a non-volatile RAM device however will significantly increase
> performance without risk.  Umem devices seem a good option for this,
> recent devices are PCI 2.2 - 64bit 66MHz and claim to sustain over
> transfer rates with no seeks, I am not sure about Linux device driver
> for that, but the old versions worked well from all accounts.
> If you put your queue on a Umem device you should get all the
performance of a
> RAM disk with all the reliability of a RAID hard drive device (better
> reliability than a hard drive as there are no moving parts).
> http://www.micromemory.com/newwebsite/Dynamic/index.asp
> > Howabout in an fs made in a file mounted looback?)
> What would be the benefit of a FS in a loopback mounted file?  That
> kill performance and reliability at the same time.

Mmm... one of the limitations of Qmail is that it creates many many
individual files (one for each email) and due to filesystem limitations,
EXT2/3 starts slowing to a crawl. Of course, another way would be to use
ReiserFS, but wouldn't doing a FS in a loopback mounted file resolve at
least that?

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