[CentOS] Software RAID muck up

Les Mikesell lesmikesell at gmail.com
Sat Jun 25 16:08:23 UTC 2005


On Sat, 2005-06-25 at 09:48, Lee W wrote:

> Just started to play with software RAID on Centos 3.5 and was trying to 
> simulate a faulty drive by using the -f switch on mdadm to mark the 
> partition (drive) as faulty and I then I removed and readded the drive, 
> which quit happily rebuilt according the /proc/mdstat and the output 
> from the --detail switch of mdadm.  After all this mucking around I 
> shutdown the system and tried to restart it in the morning but the 
> system now won't boot, it gets as far as "GRUB loading" and just stops I 
> have hard reset to get it to reboot.
> 
> I have rebooted using the install CD in rescue mode and I can see that 
> all the arrays are setup quite happily (all RAID 1's if it matters) and 
> mdstat reports the status as "dirty,no-errors".  Is that status normal? 
> all the how-tos I've seen about software RAID show this as the status, 
> so I have kind of assumed that is okay.
> 
> Given that all the data is readable from the arrays, I'm guessing that I 
> had to do something to GRUB prior after rebuilding the arrays and before 
> shutting down the system.

Grub doesn't actually boot from a RAID - it just happens to work
because RAID1 looks the same on the underlying single partitions.
Boot with the CD and point the grub config to one or the other
of the hd partitions holding /boot.  If you get an error, that
one might be corrupt and you can try the other.   If you get
to the point where the kernel is loaded and you can't mount
root, then the problem could be with RAID, but that part will
probably work.

-- 
  Les Mikesell
   les at futuresource.com





More information about the CentOS mailing list