[Exim] Re: Exim appears to be IO Bound

John P Connor <john.connor@???> wrote:
> I'm running Exim 3.02 on a Sun E250 with 512Mb memory, 2 300Mhz UltraSparcs
> and 2 18Gb mirrored disks. IMHO, this is not a "small" system (but please
> feel free to correct me). Exim is configured to accept inbound SMTP for the
> domain and forward it to the appropriate POP3 servers.
>
> Problem is, the system has started to run really slowly lately, with sar -d
> looking like this:
> [...]

Try to find out if the bottleneck is the spool or the config files. If it
is the spool and you have lots of mails sitting there for a long time,
waiting for delivery to external systems, send them over to a separate host
and deal with them there.

If it is the configuration try to minimize the number of file lookups needed.
Use dbm lookups instead of lsearch lookups. I once totally hosed the
performance of a system because, after a config change, I forgot to change
the config file back from lsearch used for easy debugging to dbm. Lsearch with
thousands of entries is really slow and hard on your disks. :-)

Also you could try to put the configuration data on a RAM disk. Although I
never tried this, it could help you. Obviously this is not a good idea to
do with the mail spool.

Jochen