[Mimedefang] MD I/O intensive?

[David F. Skoll]

On Tue, 16 Mar 2004, Les Mikesell wrote:

> That doesn't mesh with anything I've seen.  The directories where the
> file creation/deletion happened must have been tiny so the overhead
> from reiser indexing was more than the linear scan with the inode locked
> that you get with ext*.  If you accumulate more than a few hundred
> files in a single directory (queues, quarantine dir, maildirs, etc.)
> reiserfs will be faster.  There is a benchmark program here:
> http://www.netapp.com/tech_library/3022.html  that attempts to
> simulate mail handling.

If you accumulate more than a few hundred files in the mail queue,
you should consider a FallbackMX host to handle delayed mail.  Your
main host can be fast with nice small queues, and the fallback host can
be optimized for larger queues.

You can also use Sendmail queue groups to distribute queue files among
different directories.

If you accumulate more than a few hundred files in your quarantine
directory, it's time to turn off quarantining. :-)

It's pretty hard to measure file system performance on Linux because
of its aggressive caching.  Unless you have amazingly deep queues, I
don't think it makes much difference which file system you use; the
fact that you're using a mechanical disk will slow you down far more
than differences between file systems.

Regards,

David.