On Fri, Jan 21, 2011 at 07:59:22AM -0500, Josef Bacik wrote: > On Fri, Jan 21, 2011 at 09:11:23AM +0000, Jon Leighton wrote: > > Hi Josef, > > > > Thanks for the reply. > > > > On Thu, 2011-01-20 at 20:31 -0500, Josef Bacik wrote: > > > What kind of database is this? Does it use lots of files? > > > > This happens with all databases that I test with: sqlite3, mysql and > > postgresql. Which would seem to indicate that the issue is not actually > > related to the databases, but is being made evident by them when they do > > lots of reads/writes. (The jbd2 every 2 seconds thing happens even when > > all database are completely shut down.) > > > > Right I'm not trying to blame the database, more trying to get an idea the kind > of IO that they are generating so we can figure out what is being slow. > > > > When it's being > > > particularly slow could you run > > > > > > echo w > /proc/sysrq-trigger > > > > > > a couple of times, spread out. This will give us an idea of what everybody is > > > doing when things are going slow. Thanks, > > > > Cool, I have done that and attached the results. The partition in > > question (the one with the databases on) is /dev/sda4. > > > > Hrm so an fsync heavy workload it looks like. I'll run some fsync tests locally > and see if I can see the kind of slowdowns you are experiencing. Thanks, > Heh so now that I've had a moment to wake up, how about running your test on ext3, but mount the partition with mount -o barrier and see if it's still faster than ext4. Thanks, Josef -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
