Bug#485989: mdadm metadata issue

[Robert de Bath]

Sorry, long posponed email here: I'm sending it because the last 
retorical questions are still relevent.


On Wed, 16 Sep 2009, Neil Brown wrote:

> metadata=0.9 would never work.  It is a version number, not a decimal
>       number.  metadata=0.90 is correct and totally different from
>       metadata=0.9
That's what I figured.

> Do you have any idea what "upgrade script" put "metadata=0.9" in
> there?

I don't know, My best guess it that it's come from the initramdisk
creation as that's the only thing that cared, but that uses mdadm (mkconf)
to create the file. Thinking it through, I suspect it's possible that it's
a leftover from long ago and only recently has the initrd begun to care.

It would have still been created from a script or an "mdadm >> conf" though.

I note that mdadm does different lines depending on how you call it ...

# mdadm --detail --scan --config=partitions
ARRAY /dev/md0 level=raid1 num-devices=7 metadata=00.90 UUID=6daad342:4f295c4f:a3bab061:9112c3c7
ARRAY /dev/md1 level=raid10 num-devices=6 metadata=01.02 name=RIPLinuX:1 UUID=fa6457c6:33314a03:36f96c6c:5a867416
ARRAY /dev/md2 level=raid10 num-devices=6 metadata=01.02 name=RIPLinuX:2 UUID=a2070504:b2adff98:de745c49:e2623eb7
# mdadm --examine --scan --config=partitions
ARRAY /dev/md0 level=raid1 num-devices=7 UUID=6daad342:4f295c4f:a3bab061:9112c3c7
ARRAY /dev/md/1 level=raid10 metadata=1.2 num-devices=6 UUID=fa6457c6:33314a03:36f96c6c:5a867416 name=RIPLinuX:1
ARRAY /dev/md/2 level=raid10 metadata=1.2 num-devices=6 UUID=a2070504:b2adff98:de745c49:e2623eb7 name=RIPLinuX:2

Which form of the metadata would be 'right'? 
Why does --examine _sometimes_ omit it?

-- 
Rob.                          (Robert de Bath <robert$ @ debath.co.uk>)
                                              <http://www.debath.co.uk/>