On Thursday 08 March 2001 08:49, you wrote:
> On Thu, Mar 08, 2001 at 03:24:46AM +0100, Philipp Gimm wrote:
> > Anyways:
> > We have to get a mail environment up and running ASAP.
> >
> > * currently 600.000 emails per day
> > * 200.000 users/email addresses, single domain environment
> > * the system must be scalable to support 800.000 users
> > * authentication/lookup via some sort of db (not decided which yet)
> >
> > - I personally feel Exim to be the right decision on the SMTP side of
> > things.
> > - I don't really feel comfortable with the POP3 side yet. Qpopper? Is
> > Qpopper LX really that much better? However, Qpopper is the only POP3
> > server I can *really* talk about...
>
> Right, as an ex-Energis Squared (aka Planet Online) mailmaster, I know a
> fair bit. E**2 does all the technical stuff for freeserve for example.
>
> Exim is IO limited, so get some 2 gigs RAM disks. They cost about £5k
> each, but that's about the price of a compac server. However, the
> preformace of exim increases by a factor or 4-5. Thus you are effectivly
> saving money.
>
Can I just remind everyone that has a disc IO bottleneck that the software
RAID that comes with Linux (version 0.90 as provided by all the major
distributions on 2.2.x, as well as all 2.4.x kernels) is a simple, cheap way
of increasing IO bandwidth for both read and write.
Lots of 'small' SCSI 160Mhz discs on RAID 0 _really_ flys (and do so even
more if you have dual controllers as a lot of the onboard SCSI controllers
are these days).
Read the explanation as to why this is, in back of the OReilly published
Samba book.
Dirk Koopman
