On Wed, Nov 28, 2012 at 10:01 AM, Klaus Knopper
<debian-knoppix@knopper.net> wrote:
Hello again,
As a followup to the kernel 3.6.x question of JD, I have to report that
zram has a dangerous defect, probably starting around kernel 3.6.5. As
soon as data gets swapped out to the zram device, the system will freeze
because of memory corruption.
See http://code.google.com/p/compcache/issues/detail?id=102 .
There is a solution/patch to this problem, but it's still not
implemented in kernel 3.6.8. I'm currently building a patched kernel
package, since compressed swap in RAM is a quite useful feature in
Knoppix. You will find the source at
http://debian-knoppix.alioth.debian.org (probably a 3.6.8 kernel), once
it's ready.
Knoppix 7.0.4 is not affected, and I will make sure to also include the
patch in the next release if it's not already in the original kernel by
then.
Regards
-Klaus
On Mon, Nov 26, 2012 at 10:56:55AM +0100, Klaus Knopper wrote:
> Hello JD,
>
> On Sun, Nov 25, 2012 at 06:44:30PM -0700, JD wrote:
> > Hi All,
> > When I updated the kernel to 3.6, and kept updating
> > more subversion of the kernel became available, I
> > started experiencing write errors to all hard drives
> > which have ext3 or ext4 filesystems. Most of the
> > failed reads and writes were caused by the fact that
> > the drives were in standby mode, which is something
> > that is very useful for extending the life of the drive,
> > but which the kernel disk drivers in 3.6.X did not take
> > into account, and thus many failed reads and writes.
> >
> > This problem was not there prior to kernel 3.6!!!
> >
> > And indeed I confirmed this by booting into 3.5.X
> > and 3.4.X.
> >
> > I hope this is helpful to people who might otherwise
> > think their drives are bad.
>
> This sounds like a serious kernel bug, which I would not expect
> occurring in the recent "stable" >= 3.6.7 kernels.
>
> I just uploaded a kernel package that I would like to include in Knoppix
> 7.0.5 I had no problems on my testing computers, but maybe you can
> recheck by installing these packages (and the static kernel part) on
> your system, and tell if the errors still occur?
>
> http://debian-knoppix.alioth.debian.org/packages/linux-source-3.6.7/
>
> This version has aufs and cloop patched in.
>
> Regards
> -Klaus