[CentOS] Re: Major problem with software raid

Fri Jul 27 02:22:45 UTC 2007
ajulvestad <ajulvestad at n4f.no>

Johnny Hughes writes:

> ajulvestad wrote:
>> Ok, this is the case: 
>> 
>> I've got two raid-5 arrays with software raid, both with three disks.
>> Setup:
>> md0 has hdb2, hdd1 and sda1
>> md1 has hdb5, hdd3 and sda3
>> Tonight, the system lost power due to a power spike. The result was a
>> reboot where it attempted to fix the raid, but it didn't exactly work. I
>> have now booted a live CD and using utilities there.
>> It seems the checksum value is slightly off for all disks. And the
>> update time is the same for some disks, but not all.
>> When I try mdadm --assemble /dev/md1 (or md0) with various options like
>> force, scan, auto, etc - I get error messages like only 1 drive found,
>> not enough.. no disks found and no mention of md0/1 found in config file.
>> What should I do? Which partitions (two in each array) do I pick as
>> "these two are the one I should rebuild with"? And how do I actually
>> FORCE mdadm to start an array with those two set devices?
>> See files in http://gandalf.n4f.no/~aj/md/ for output from mdadm.
>> Assistance deeply appreciated...
> 
> http://tldp.org/HOWTO/Software-RAID-HOWTO-8.html

Thank you for the URL, but I have already seen the howto. Running   mdadm 
 --assemble --force only provides the message that there is only one disk 
available. So what I'm looking for is a way to tell mdadm exactly what 
devices to use for the array.