and don't forget it's not 100% of the time, it's about 50% of the time
3.3 gives a problem so not sure if it's an uninitialized variable or
something like that?   3.2.6 works 100% of the time.  And again on
RAID0 - RAID1 haven't seen a problem.

On Tue, Nov 19, 2013 at 11:45 AM, Martin Wilck [off-list ref] wrote:

On 11/19/2013 01:01 AM, NeilBrown wrote:

quoted

On Mon, 18 Nov 2013 15:13:58 -0800 "David F." [off-list ref] wrote:

quoted

output of 'mdadm --assemble --scan --no-degraded -v' (mdadm 3.2.6):

...

quoted

mdadm: no RAID superblock on /dev/sdc2

quoted

output1 of 'mdadm --assemble --scan --no-degraded -v' (mdadm 3.3 -
note using /dev/sdc2, not /dev/sdc):

.....

quoted

mdadm: /dev/sdc2 is identified as a member of /dev/md/imsm0, slot -1.

So there is the problem.  mdadm 3.2.6 sees no RAID superblock on sdc2, while
mdadm 3.3 does (but should not).


However that code hasn't changed!

load_super_imsm() still starts with:


      if (test_partition(fd))
              /* IMSM not allowed on partitions */
              return 1;

Well not quite - you changed that code in commit b31df436 "intel,ddf:
don't require partitions when ignore_hw_compat is set". Maybe there's
something wrong with that ignore_hw_compat logic?

In the strace I don't see indication of test_partition having been
called, that's another hint in that direction.

Martin

quoted

and test_partition hasn't changed since it was written in April 2010 for
mdadm 3.1.3.

So I'm quite perplexed.

Is your mdadm-3.3 compiled from source or provided by a distro?

Can you run the "mdadm --assemble" under strace and post the result?

  strace -o /tmp/some-file mdadm --assemble --scan ......

Thanks,
NeilBrown