Intel Software RAID and dmraid problem

[Bas Mevissen]

Amin Amir Ahmadi wrote:
> Dear All,
> 
> I have a problem with dmraid and Intel Software RAID1 on Redhat Fedora 
> Core 6. I setup RAID1 in BIOS with 2 hard disk and then I installed 
> Redhat Fedora Core 6. During installation Fedora recognized only one 
> drive (device-mapper) and was installed successfully. When one of my 
> hard drives failed, I replaced it with another one and I imported it 
> into RAID array, the RAID status in BIOS became "Rebuild" but during 
> boot time I received kernel panic message and my system could not load 
> the operating system. For more information I should say that my RAID 
> Controller is "ICH8DO" and my motherboard is "AIMB-764".
> 

AFAIK, that "rebuild" is just a flag, but does not actually sync the
both disks.

Best thing is to boot from some live cdrom or dvd and copy all data from
the old drive to the new one.

Please be careful when relying on dmraid and the mkinitrd and
initscripts to make proper initial ramdisks (initrd). I'm still sorting
out why my initrd's are not correct. I've traced this down to a bug in
the function resolve_dm_name in /etc/init.d/functions.

So please always manually check your initrd's init script to contain
calls to dmraid and kpartx before booting a new kernel.

How to extract an initrd:
zcat your_initrd.img  > initrd
# replace your_initrd.img with the proper name
mkdir xx; cd xx
cpio -id <../initrd

less init # search for dmraid and kpartx

P.S. Please consider upgrading to something newer than FC6. It is
unsupported for a long time. So not even serious security problems will
be fixed!

Best Regards,

Bas.