Thomas, > Regarding the "few milliseconds" -> are you sure that we are talking > abust "just a few" of them? Time ago I dedicated 1 GB tmpfs to each > Amavis Host, and it seemed that this really improved I/O performance. > However, I did not run any benchmarks proving this.
It very much depends on the file system in use, and on disks behind it. Back in the old days when I started my work on amavis we were running Tru64 Unix on Alphas, and there it made a huge difference when I introduced a permanently open temporary file, and temporary directories that stay undeleted for the lifetime of a process. This is because meta operations on a file system (creating/deleting a file and especially a directory) are very expensive on a classical file system. My next experience in this area is when I was trying to benchmark amavisd on a personal computer, with commodity ATA disks. It turned out that due to a disk cache and the typical ATA disk lying to the OS that it has completed writes, there was hardly any difference between using a ramdisk and using a cached ATA disk for a temporary area in amavisd. SCSI disks are not in the habit of lying about completed writes, so it depends more on the choice of a file system. With modern journalling file systems or UFS2 the penalty of fs meta operation is hardly greater that disk I/O. There would be some performance difference between a ram disk and a journalling fs on a true disk, although not that much. But yes, the true answer lies in benchmarking each platform. > Cleanup cronjobs are running each night and removing files older than > 2 days. Max allowed mail size is 100MB, 40 Amavis processes on each > host. I never noticed tmpfs filling up, I'm not even monitoring it. > However, if my front MX servers queue is filling up, immediately at > least two people get a notice. Yes, monitoring a queue filling-up suffices. Mark ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ AMaViS-user mailing list AMaViS-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/amavis-user AMaViS-FAQ:http://www.amavis.org/amavis-faq.php3 AMaViS-HowTos:http://www.amavis.org/howto/
