[tlug] Re: limitation on using md0 as /

[Nobuyoshi KAMEI <zic-tlug@example.com>]

I've found the cause and solved the issue.

(1) I had to eliminate all the "DEVICE" lines from mdadm.conf, which is 
equivalent effect to placing a single line "DEVICE partitions" in the file.


(2) There was a typo in the md0 definition.

>> Here is md0 definition:
>>	ARRAY /dev/md0 level=raid1 num-devices=4
>>	devices=/dev/sda2,/dev/sdc1,/dev/sdb15,/dev/sdd5

Actually, it was defined as this.

>> ARRAY /dev/md0 level=raid1 num-devices=3 
UUID=789037b0:57ae8fb9:4b0dc79c:e4a9fd41 
devices=/dev/sda2,/dev/sdc1,/dev/sdb15,/dev/sdd5

Obviously, "num-devices=3" was incorrect.

I corrected it to "num-devices=4" and "mdadm -As --auto=yes -R /dev/md0" 
worked as expected.


(3) then I recreated initrd, rebooted, and it worked fine.


--
zic


Nobuyoshi KAMEI さんは書きました:
>  >> Message-ID: <20080227114908.bd78a9c9.attila@example.com>
>
>  >> Make sure you have support for SCSI disks(CONFIG_BLK_DEV_SD) 
> compiled in.
>  >> I had the same issue on a leased server and it took
>  >> me a while to figure that out (mostly because i only
>  >> got the last 24 lines of the kernel output, which didn't
>  >> contain the important stuff)
>
>
> Thanks for the reply but not sure what you mean.
>
> sd_mod.ko is a module and it has been in initrd all the time since long 
> time ago.
>
> It used to work in that way so I assume that is not the root cause.
>
>
> I've examined initrd-2.6.23.15-137.fc8.img which was an gzip cpio image, 
> and found init script, and there are lines,
>
>  >> mkblkdevs
>  >> mdadm -As --auto=yes --run /dev/md0
>
> so maybe the right question would be,
>
> Why "mdadm -As --auto=yes --run /dev/md0" fails to detect md0 while 
> "/sbin/mdadm -Ac partition -m 0 /dev/md0" succeeds ?
>
> -
> zic