[mythtv-users] OT: RAID rebuild with the wrong partition

Yan Seiner yan at seiner.com
Sun Sep 12 16:01:30 UTC 2010

John Drescher wrote:
>> Hmmm...on second read of your message, it sounds like you've already managed
>> to get the arrays back together again with the right members, and now you're
>> just deailing with the filesystem.  Doing an XFS repair from a live CD seems
>> logical, although I'm afraid that if the md3 array was already re-built and
>> synced with an incorrect member, the damage may already be done, and you may
>> have to restore from backups, depending on how bad it is.
> I am still confused how this could possibly happen. I mean syncing for
> a raid 1 would be choosing 1 of the array members and copying all of
> the data to the other member. If the source was a disk in the raid6
> array then md3 would be totally unreadable. If the source was from the
> original array then no corruption would occur.
Exactly.  A raid-1 is a mirror; the data should be OK unless the fs 
itself crashed, independent of raid.

If the system rebuilt somehow using the wrong partition - and I don't 
see how that could happen - then you'd have a functioning raid with two 
partitions; just different ones.

So for files to be missing, that means the fs is borked.

If the device names are moving around, you may have flaky hardware, or 
you may have left something plugged in.  My daughter's PC won't boot if 
she leaves her mp3 player plugged in; the stupid bios *always* prefers a 
USB drive to an SATA for booting....

So maybe you had a usb stick or something plugged in and it shifted the 
device names around, you interrupted the rebuild halfway through, and 
ended with an inconsistent RAID that then got rebuild using the 
incomplete image?


   ,>/'_         o__
   (_)\(_)       ,>/'_          o__
A day may come  (_)\(_)         ,>/'_      o__
when the courage of men fails, (_)\(_)     ,>/'_ 
when we forsake our friends and break all (_)\(_)
bonds of fellowship, but it is not this day.
It is not this day!
This day we ride!

More information about the mythtv-users mailing list