I just upgrades one of our newsservers from 2.6.9 to 2.6.11. I
use "iostat -k -x 2" to see live how busy the disks are. But
I don't believe that Linux optimizes things so much that a disk
can be 1849.55% busy :)
(you'll have to stretch out your xterm to be able to read this):
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
hda 0.00 50.00 0.00 18.18 0.00 545.45 0.00 272.73 30.00 2.35 129.00 86.25 156.82
hdc 0.00 45.45 77.27 31.82 3927.27 618.18 1963.64 309.09 41.67 6.27 57.42 38.42 419.09
hdd 4.55 0.00 63.64 0.00 68.18 0.00 34.09 0.00 1.07 1.11 17.43 17.43 110.91
hde 477.27 0.00 45.45 0.00 522.73 0.00 261.36 0.00 11.50 0.40 8.90 8.90 40.45
hdg 18.18 70154.55 22.73 172.73 40.91 70727.27 20.45 35363.64 362.07 1010.36 1127.72 94.63 1849.55
With 2.6.9, %util never came above 100% (and that was indeed "fully loaded".
I have systems with a comparable load running 2.6.10 and 2.6.11-rc3-bk4
that also don't show this behaviour (but those are SCSI, not IDE).
I use CFQ, but changing that to deadline doesn't make a difference.
Mike.
"Miquel van Smoorenburg" <[email protected]> wrote:
>
> I just upgrades one of our newsservers from 2.6.9 to 2.6.11. I
> use "iostat -k -x 2" to see live how busy the disks are. But
> I don't believe that Linux optimizes things so much that a disk
> can be 1849.55% busy :)
>
> (you'll have to stretch out your xterm to be able to read this):
>
> Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
> hda 0.00 50.00 0.00 18.18 0.00 545.45 0.00 272.73 30.00 2.35 129.00 86.25 156.82
> hdc 0.00 45.45 77.27 31.82 3927.27 618.18 1963.64 309.09 41.67 6.27 57.42 38.42 419.09
> hdd 4.55 0.00 63.64 0.00 68.18 0.00 34.09 0.00 1.07 1.11 17.43 17.43 110.91
> hde 477.27 0.00 45.45 0.00 522.73 0.00 261.36 0.00 11.50 0.40 8.90 8.90 40.45
> hdg 18.18 70154.55 22.73 172.73 40.91 70727.27 20.45 35363.64 362.07 1010.36 1127.72 94.63 1849.55
>
> With 2.6.9, %util never came above 100% (and that was indeed "fully loaded".
> I have systems with a comparable load running 2.6.10 and 2.6.11-rc3-bk4
> that also don't show this behaviour (but those are SCSI, not IDE).
>
> I use CFQ, but changing that to deadline doesn't make a difference.
>
Mike, did you ever get to the bottom of this? Still happening in 2.6.12-rc1?
On Mon, 21 Mar 2005 23:09:42, Andrew Morton wrote:
> "Miquel van Smoorenburg" <[email protected]> wrote:
> >
> > I just upgrades one of our newsservers from 2.6.9 to 2.6.11. I
> > use "iostat -k -x 2" to see live how busy the disks are. But
> > I don't believe that Linux optimizes things so much that a disk
> > can be 1849.55% busy :)
> >
> > (you'll have to stretch out your xterm to be able to read this):
> >
> > Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
> > hda 0.00 50.00 0.00 18.18 0.00 545.45 0.00 272.73 30.00 2.35 129.00 86.25 156.82
> > hdc 0.00 45.45 77.27 31.82 3927.27 618.18 1963.64 309.09 41.67 6.27 57.42 38.42 419.09
> > hdd 4.55 0.00 63.64 0.00 68.18 0.00 34.09 0.00 1.07 1.11 17.43 17.43 110.91
> > hde 477.27 0.00 45.45 0.00 522.73 0.00 261.36 0.00 11.50 0.40 8.90 8.90 40.45
> > hdg 18.18 70154.55 22.73 172.73 40.91 70727.27 20.45 35363.64 362.07 1010.36 1127.72 94.63 1849.55
> >
> > With 2.6.9, %util never came above 100% (and that was indeed "fully loaded".
> > I have systems with a comparable load running 2.6.10 and 2.6.11-rc3-bk4
> > that also don't show this behaviour (but those are SCSI, not IDE).
> >
> > I use CFQ, but changing that to deadline doesn't make a difference.
> >
>
> Mike, did you ever get to the bottom of this? Still happening in 2.6.12-rc1?
Sortof... (I already posted this before:) the siimage.c driver was broken for me with
2.6.11. Lots of IDE warning messages to /dev/console @ 9600 baud also makes
things slow and weird. I couldn't find what caused this, though, there
weren't much (if any) changes in siimage.c so it must have been something
different. Perhaps the IRQ changes.
I moved to sata_sil.c and everything now works fine. I tried sata_sil around 2.6.5
or so, and it was very unstable, but I was pleasantly surprised to see that
the new SATA code has come a long way.
So I still don't know what the _actual_ problem was, but the solution is
"use libata instead of the old IDE driver". As "make menuconfig" tells you
something similar it's probably an acceptable solution.
Mike.