From mboxrd@z Thu Jan  1 00:00:00 1970
From: Tyler <pml@dtbb.net>
Subject: BUGREPORT: mdadm v2.0-devel - can't create array using version 1
 superblock, possibly related to previous bugreport
Date: Tue, 03 May 2005 04:15:19 -0700
Message-ID: <42775D47.4000805@dtbb.net>
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To: neilb@cse.unsw.edu.au
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List-Id: linux-raid.ids

When i try to create any raid5/raid6 array with --metadata 1 or 
--metadata 1.0, it simply spits out a response saying /dev/hdX is 
busy... X being whichever drive i listed as an array member first on the 
list of drives.  1.x.0 doesn't support version 1 superblocks, but i used 
it as an example below without the metadata option to show that creating 
the raid works fine, and then the same with mdadm v2.0-devel, they 
create fine until you add the metadata option.  Kernel is 2.6.12-rc3-mm2.

First I create an array using v1.9.0 successfully (from system path):

root@localhost:~/dev/mdadm-2.0-devel-1# mdadm -C -l 5 -n 3 /dev/md0 
/dev/hdb /dev/hdc /dev/hdd
mdadm: array /dev/md0 started.
root@localhost:~/dev/mdadm-2.0-devel-1# mdadm -S /dev/md0

Then successfully create an array with default superblock (0.90?) using 
v2.0-devel (from current dir):

root@localhost:~/dev/mdadm-2.0-devel-1# ./mdadm -C -l 5 -n 3 /dev/md0 
/dev/hdb /dev/hdc /dev/hdd
mdadm: /dev/hdb appears to be part of a raid array:
    level=5 devices=3 ctime=Tue May  3 11:42:28 2005
mdadm: /dev/hdc appears to be part of a raid array:
    level=5 devices=3 ctime=Tue May  3 11:42:28 2005
mdadm: /dev/hdd appears to be part of a raid array:
    level=5 devices=3 ctime=Tue May  3 11:42:28 2005
Continue creating array? y
VERS = 9002
mdadm: array /dev/md0 started.
root@localhost:~/dev/mdadm-2.0-devel-1# ./mdadm -S /dev/md0

Then try creating a raid with version 1 superblock, which fails:

root@localhost:~/dev/mdadm-2.0-devel-1# mdadm -C -l 5 -n 3 --metadata 1 
/dev/md0 /dev/hdb /dev/hdc /dev/hdd
mdadm: /dev/hdb appears to be part of a raid array:
    level=5 devices=3 ctime=Tue May  3 11:43:00 2005
mdadm: /dev/hdc appears to be part of a raid array:
    level=5 devices=3 ctime=Tue May  3 11:43:00 2005
mdadm: /dev/hdd appears to be part of a raid array:
    level=5 devices=3 ctime=Tue May  3 11:43:00 2005
Continue creating array? y
VERS = 9002
mdadm: ADD_NEW_DISK for /dev/hdb failed: Device or resource busy

I believe it *could* have something to do with the fact that mdadm 
2.0-devel doesn't detect previously written (and/or blanked) raid 
superblocks, look at my previous bugreport I filed a few minutes ago.  
Maybe its seeing what the --examine feature shows, that there's an 
"active" array on the drive still, hence, being unable to create a new one.