On Tue, Jan 14, 2003 at 11:33:54PM -0800, Jeff Kilbride wrote: > Are there any general guidelines for optimizing ext3 for MySQL? I have a > perl script that runs 200K + updates into my database once a day and I see > pretty wildly fluctuating query/sec numbers using Jeremy Z's mytop program. > I've seen in excess of 2000 qps and then seen that number drop to 40 qps. > The average seems to be about 200 qps, which seems kinda slow given my > hardware: > > Dual P3 1.3MHz > 1GB RAM > Dual SCSI drives (160 MB/s) > RedHat 7.3 > MySQL 3.23.53a w/MyISAM tables > This particular table being updated has about 5 million rows. The fields > being updated are not indexed.
By "updated" you mean inserts? Or are you doing a table scan for each update (since they're not indexed)? > Also, the qps numbers seem to slow down every 5 seconds or so, which I think > matches the default write timing for the ext3 journal. Can anybody share > their experience with optimizing ext3 -- i.e. which mode is best (writeback, > ordered, journal) and any parameters that can be tuned? Any insight is > appreciated. Yeah, 5 seconds is the ext3 default. You can tune it. I recently saw someone suggest this: # set disk flush to 30,000 clicks or 5 minutes echo "30 64 64 256 30000 3000 60 0 0" > /proc/sys/vm/bdflush But have not tried it myself. Jeremy -- Jeremy D. Zawodny | Perl, Web, MySQL, Linux Magazine, Yahoo! <[EMAIL PROTECTED]> | http://jeremy.zawodny.com/ MySQL 3.23.51: up 31 days, processed 1,040,147,810 queries (381/sec. avg) --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
