Re: Md corruption using RAID10 on linux-2.6.21

[Neil Brown <neilb@suse.de>]

On Wednesday May 16, dondster@gmail.com wrote:
...
> 
> The problem arises when I do a drive removal such as sda and then I
> remove power from the system. Most of the time I will have a corrupted
> partition on the md device. Other corruption will be my root partition
> which is an ext3 filesystem. I seem to have a better chance of booting
> a least 1 time with no errors with bitmap turned on, but If I repeat
> the process, I will have corruption as well. Also with bitmap turned
> on, adding the new drive into the md device will take way to too long.
> I only get about 3MB per second on the resync. With bitmap turned off,
> I will get between 10MB to 15MB resync rate. Has anyone else seen this
> behavior, or is this situation is no tested very often? I would think
> that I shouldn't get corruption with this raid  setup and jornaling of
> my filesytems? Any help would be appreciated.


The resync rate should be the same whether you have a bitmap or not,
so that observation is very strange.  Can you double check, and report
the contents of "/proc/mdstat" in the two situations.

You say you have corruption on your root filesystem.  Presumably that
is not on the raid?  Maybe the drive doesn't get a chance to flush
it's cache when you power-off.  Do you get the same corruption if you
simulate a crash without turning off the power. e.g.
   echo b > /proc/sysrq-trigger

Do you get the same corruption in the raid10 if you turn it off
*without* removing a drive first?

NeilBrown