Re: mdadm --detail showing annoying device

[Neil Brown <neilb@suse.de>]

On Wednesday October 21, stephane.bunel@forumdesimages.fr wrote:
> Hi,
> 
> I'm a newbie in the mdadm world. I defined some udev rules to make disk 
> staticly named according to the bus/host/target. I.e. /dev/sda become 
> /dev/raid_disk0. So nothing very special with that, it's just a convenient way 
> to assign disk name to it's physical location.
> 
> #ls -la /dev/raid*
> brw-rw---- 1 root disk 8,  0 2009-10-16 18:12 /dev/raid_disk0
> brw-rw---- 1 root disk 8, 16 2009-10-16 18:12 /dev/raid_disk1
> 
> A RAID1 (/dev/md0) is assembled over this two disk.
> When looking for detailed information, mdadm show annoying device name in 
> place of /dev/raid_disk*:
> 
....
>      Number   Major   Minor   RaidDevice State
>         0       8        0        0      active sync   /dev/char/21:0
>         1       8       16        1      active sync   /dev/char/21:1

What is a block device doing in /dev/char ???  There should only be
character devices in there.

If these are actually block device, then I think there is something
wrong with your udev rules.
If these are char devices, then mdadm is doing the wrong thing, but I
cannot see that from the code.

Your proposal of choosing the highest rather than the shortest name
has some merit, but I your current situation doesn't seem to justify
it, and I particularly like the simplicity of the current heuristic.

So for now I think I'll leave it as it is and encourage you to fix
your udev rule.

Thanks,
NeilBrown