* Victor Duchovni <victor.ducho...@morganstanley.com>: > On Sat, Jan 23, 2010 at 06:08:40PM +0100, Stefan Foerster wrote: > > In case of severe server "overload", with postscreen(8) complaining > > about lookup and update times around 400ms almost every mail, is it > > (reasonably) safe as a last desperate measure to put $data_directory, > > or at least the file referenced by $postscreen_cache_map, on a ramdisk > > (e.g. "tmpfs" with Linux)? > > Yes, but I would still try to find out why the lookup times are so > absurdly large?
An exotic bug in the raid controller's firmware of the three servers slowed down access to certain parts of the raid array to the speed of molasses. It affected /var (and /boot), but not the LV which held $queue_directory. On the fourth, identical server, a slightly different disk layout was used for all testing and benchmarking. After verifying that the unattended installation worked, the three other servers were deployed into production with a larger LV for /usr. Upgrading the faulty firmware solved the problem. N.B: If you bother with testing at all, do it right. Stefan
