Re: MDADM 3.3 broken?

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

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

...

mdadm: no RAID superblock on /dev/sdc2

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

.....

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;


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