So I just tested writeback on my desktop computer which exhibits the same problems. I mounted both the root filesystem and /home with data=writeback (ext3).
So far the difference is *huge*! The system is much more responsive - I'm writing this while 'stress -d 4' is running in the background. The same applies to the dd test - all apps respond almost instantly with writeback, as opposed to sluggish and hanging with ordered. Applications open much faster as well.... I'll do some more testing to confirm - mainly writeback only on /home vs root and also on my laptop. Is this a bug in ext3 then, or is ordered mode supposed to be so slow / problematic on desktop systems? What problems might occur when using writeback mode? I'm a bit concerned about the following comment from the mount manual: It guarantees internal filesystem integrity, however it can allow old data to appear in files after a crash and journal recovery. By the way, to use writeback on the root filesystem, setting data=writeback in fstab only is not sufficient. As 'man mount' states: To use modes other than ordered on the root filesystem, pass the mode to the kernel as boot parameter, e.g. rootflags=data=journal. - Johannes On Wed, Jun 23, 2010 at 11:52 AM, Johannes H. Jensen <j...@pseudoberries.com> wrote: > I haven't tried writeback, no. Is it possible to remount with this > option, or do I need to modify fstab and reboot? > > - Johannes > > > On Wed, Jun 23, 2010 at 10:00 AM, Peter Hoeg <pe...@hoeg.com> wrote: >> Have you tried mounting the filesystems with writeback instead of >> ordered? >> >> /peter >> >> On Wed, Jun 23, 2010 at 15:42, Johannes H. Jensen <j...@pseudoberries.com> >> wrote: >>> I just tested with the anticipatory scheduler on the stock Ubuntu >>> 2.6.32: >>> >>> # echo anticipatory > /sys/block/sda/queue/scheduler >>> >>> This did not seem to have any effect - the problem was still very much >>> present. >>> > -- Heavy Disk I/O harms desktop responsiveness https://bugs.launchpad.net/bugs/131094 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
