[CentOS] *very* ugly mdadm issue

Tue Sep 2 20:03:35 UTC 2014
m.roth at 5-cent.us <m.roth at 5-cent.us>

Les Mikesell wrote:
> On Tue, Sep 2, 2014 at 1:33 PM,  <m.roth at 5-cent.us> wrote:
>>> But sdd _should_ have the correct data - it just isn't being detected
>>> as a raid member.   I think with smaller devices - or at least devices
>>> with smaller partitions and FD type in the MBR it would have worked
>>> automatically with the kernel autodetect.
>> Anyway, the upshot was my manager was rather annoyed - I *should* have
>> pulled sdc, and put in a new one, and just let that go. I still think it
>> would have failed, given the inability of mdadm to find the info on sdd.
>> We wound up just remaking the RAID, and rebuilding the mirror over the
>> weekend.
> I think either adding the ARRAY entry in /etc/mdadm.conf and rebooting
> or some invocation of mdadm could have revived /dev/md4 with /dev/sdd
> (and the contents you wanted) active.

Tried that. No joy.