[CentOS] Re: Raid5 issues

Feizhou feizhou at graffiti.net
Sun May 6 01:59:01 UTC 2007


> Error adding sda to set silxxxxxxx: Raid type 234 is not supported.  
> (This is from memory, so probably not exactly correct).
> I tried updating the bios, but I can't even seem to do that.  It won't 
> boot off the floppy, and when I boot of any dos based cdrom, I can't see 
> the floppy.  (I have external usb floppy.  The internal one doesn't seem 
> to work).

1) Blow away the RAID array in the bios of the raid card. 2) Reinstall 
and make sure you have /boot on its own raid1'ed partitions under the 
1024 cylinder limit since you have an old box. 3) If the motherboard 
bios don't give you a boot off board disk controller option. then make 
yourself a grub floppy to handle the kernel and initrd image loading. 
This is just a grub floppy. no kernel, no initrd image will stored on 
the floppy. Its sole purpose is to provide you a way to load the kernel 
and its initrd image from disk.

You will never be able to boot of a fakeraid from a normal installation 
procedure. If you are dead set on doing that, you have to get the dmraid 
driver loaded during the installation process and the grub installation 
must be done to the dm device. Another thing is, the dmraid driver in 
raid 1 does not support failover when a disk dies, it only knows 
mirroring. Have fun.



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