Re: RAID1 "out of memory" error, was Re: 2.6.21-rc5-mm4

["Dan Williams" <dan.j.williams@intel.com>]

On 4/5/07, Andrew Morton <akpm@linux-foundation.org> wrote:
> On Fri, 06 Apr 2007 02:33:03 +1000
> Reuben Farrelly <reuben-linuxkernel@reub.net> wrote:
>
> > Hi,
> >
> > On 3/04/2007 3:47 PM, Andrew Morton wrote:
> > > ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.21-rc5/2.6.21-rc5-mm4/
> > >
> > > - The oops in git-net.patch has been fixed, so that tree has been restored.
> > >   It is huge.
> > >
> > > - Added the device-mapper development tree to the -mm lineup (Alasdair
> > >   Kergon).  It is a quilt tree, living at
> > >   ftp://ftp.kernel.org/pub/linux/kernel/people/agk/patches/2.6/editing/.
> > >
> > > - Added davidel's signalfd stuff.
> >
> > Looks like some damage, or maybe intolerance to on-disk damage, to RAID-1.
> >
> > md1 is the first array on the disk, and it refuses to start up on boot, or after
> > boot.
> >
> > ...
> >
> > tornado ~ # mdadm --assemble /dev/md1 /dev/sda1 /dev/sdc1
> > mdadm: device /dev/md1 already active - cannot assemble it
> > tornado ~ # mdadm --run /dev/md1
> > mdadm: failed to run array /dev/md1: Cannot allocate memory
> > tornado ~ #
> >
> > and looking at a dmesg, this is logged:
> >
> > md: bind<sdc1>
> > md: bind<sda1>
> > raid1: raid set md1 active with 2 out of 2 mirrors
> > md1: bitmap initialized from disk: read 0/1 pages, set 0 bits, status: -12
> > md1: failed to create bitmap (-12)
> > md: pers->run() failed ...

Is this the dmesg from boot or the dmesg after running the mdadm --run command?

> >
> > tornado ~ # uname -a
> > Linux tornado 2.6.21-rc5-mm4 #1 SMP Thu Apr 5 23:47:42 EST 2007 x86_64 Intel(R)
> > Pentium(R) 4 CPU 3.00GHz GenuineIntel GNU/Linux
> > tornado ~ #
> >
> > The last known version that worked was 2.6.21-rc3-mm1 - I haven't been testing
> > out the -mm releases so much lately.
>
> OK.  I assume that bitmap->chunks in bitmap_init_from_disk() has some
> unexpectedly large value.
>
> I don't _think_ there's anything in -mm which would have triggered this.
> Does mainline do the same thing?
>
> I guess it's possible that the code in git-md-accel.patch accidentally
> broke things.  Perhaps try disabling CONFIG_DMA_ENGINE?
>

git-md-accel.patch does not touch anything in the raid1 path, but I
guess stranger things have happened.

--
Dan