On Fri, 5 Oct 2007, Rob Mueller wrote: > b) make sure you have the right filesystem (on linux, reiserfs is much > better than ext3 even with ext3s dir hashing) and journaling modes A data point regarding reiserfs/ext3: We are in the process of moving from reiserfs to ext3 (with dir_index). ext3 seems to do substantially better than reiserfs for us, especially for read heavy loads (squatter runs at least twice as fast as it used do). I think that this is partly because ext3 does more aggressive read ahead (which would be a mixed blessing under heavy load), partly because reiserfs suffers from fragmentation. I imagine that there is probably a tipping point under the sort of very heavy load that Fastmail see. data=ordered in both cases. data=journal didn't seem to make any difference with ext3. data=journal with reiserfs caused amusing kernel memory leaks, which it looks like Fastmail also hit recently. An dedicated journal device would probably make a big difference with data=journal. -- David Carter Email: David.Carter@xxxxxxxxxxxxx University Computing Service, Phone: (01223) 334502 New Museums Site, Pembroke Street, Fax: (01223) 334679 Cambridge UK. CB2 3QH. ---- Cyrus Home Page: http://cyrusimap.web.cmu.edu/ Cyrus Wiki/FAQ: http://cyrusimap.web.cmu.edu/twiki List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html
