[rescue] G4 pricing
abuse at cabal.org.uk
Fri Aug 18 03:23:56 CDT 2006
On 17 Aug 2006, at 22:08, Mike Meredith wrote:
> On Thu, 17 Aug 2006 19:48:05 +0100, Peter Corlett wrote:
>> In any case, disk is cheap and you might as well have loads of swap
>> on a Linux box and use it to back tmpfs on /tmp, /var/spool/exim4/
>> cache and so on.
> Ouch! Most of /var/spool/exim certainly doesn't belong on a tmpfs
> filesystem ... an MTA is supposed to ensure that a message is securely
> written to non-volatile storage before returning the final 'OK' in an
> SMTP session. It's fine to have /var/spool/exim/db on tmpfs though ...
> which is the hottest point of that hot directory.
Mail.app broke that line inappropriately, and I got the name of the
directory slightly wrong. The spool is, indeed, on a regular ext3
filesystem, albeit inside a Xen domU where I suspect the fsync()s
don't cause an *immediate* flush to disk but only when the dom0 gets
round to it up to 30s later.
> Of course I'm somewhat prejudiced in this matter being an old-
> mail administrator ... in reality modern systems are reliable enough
> that you may choose to put /var/spool/exim on tmpfs and cope with the
> risk of lost messages.
Ah, no, I wouldn't personally do that. I *would* consider using a
solid-state disk for spool, but they're not at all the same thing,
and expensive enough that building another mailserver may be more
I think we're both actually singing from the same songsheet here.
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