On Thu, Jun 24, 2010 at 1:48 AM, Johannes H. Jensen <j...@pseudoberries.com>wrote:
> 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 direct subscriber > of the bug. > > Status in The Linux Kernel: Invalid > Status in “linux” package in Ubuntu: Confirmed > Status in “linux-source-2.6.22” package in Ubuntu: Won't Fix > > Bug description: > Binary package hint: linux-source-2.6.22 > > When compared with 2.6.15 in feisty, heavy disk I/O causes increased iowait > times and affects desktop responsiveness in 2.6.22 > > this appears to be a regression from 2.6.15 where iowait is much lower and > desktop responsiveness is unaffected with the same I/O load > > Easy to reproduce with tracker - index the same set of files with 2.6.15 > kernel and 2.6.22 kernel and the difference in desktop responsiveness is > massive > > I have not confirmed if a non-tracker process which does heavy disk i/o > (especially writing) replicates this yet - will do further investigation > soon > > To unsubscribe from this bug, go to: > https://bugs.launchpad.net/linux/+bug/131094/+subscribe > I'm using Ext4 and when I try to use data=writeback for my root partiton (it was ext3 and converted to ext4), I get a error while booting which indicates "unable to change mode from ordered to writeback while remounting".. I think it is another bug.. Anyone else seeing this? -- 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