On Wed, Jan 27, 2010 at 02:06:25PM +0100, Andre Noll wrote: > On 11:19, bugzilla-daemon@xxxxxxxxxxxxxxxxxxx wrote: > > After kill -9 of the sync run it took about 20 minutes before > > it died. > > I was seeing similar behaviour on one of our servers, and changing > the io scheduler to noop fixed things for me. So it seems to be an > issue with cfq which is somehow triggered by ext4 but not by ext3. > > To change the IO scheduler, just execute > > echo noop > /sys/block/sda/queue/scheduler > > (replace sda if necessary). Andre or Michael. If switching away from cfq helps, that's definitely... interesting. Given that cfq is the default scheduler, I definitely want to understand what might be going on here. Are either if you able to run blktrace so we can get a sense of what is going on under the cfq and deadline/noop I/O schedulers? And in both of your cases, were you using a new file system freshly created using mke2fs -t ext4, or was this a ext2/ext3 filesystem that was converted for use under ext4? Thanks, - Ted -- 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
