I decided that this message is better for Debian-ISP, so I replied to the list and BCC'd you. I hope you don't object.
On Sun, 18 Aug 2002 01:20, you wrote: > I'm having some trouble finding info on this stuff and found a > knowledgeable-sounding post of yours on debian-isp. Please ignore if > this is inappropriate. > > I'm going to setup a debian woody system for qmail (and others) and was > hoping to secure the qmail queue a bit. For some reason, sync mounted > ext2 and 3 is abysmally slow. How does FFS do it? anyway, do you know > if ext3 mounted data=journal (or any other way) is sufficient? I have not done any serious tests on such things. If you want to do such tests then I recommend my Postal benchmark program (it's in Debian). But don't try the IMAP option - I haven't finished coding it. Rumour has it that data=journal can actually improve performance in some situations. If a program is writing lots of small files synchronously (quite common for a mail server that has one tiny control file for every message, and the average message file isn't too big) then journalling the data allows for synchronous writes to a small (8M to 32M) region on disk (which is really fast) and it'll then be written to it's final destination with the write-back caching enabled which allows writes to be ordered for good performance. I haven't tested this but it all sounds logical. Without the data=journal option ReiserFS is rumoured to beat Ext3, with data=journal ext3 should win. I don't know much about FFS. I would be interested in seeing benchmark data. Also one thing I have been thinking of doing is benchmarking Qmail vs Postfix... ;) Russell Coker
