[ale] md0 tasks taking 60-80% of CPU

[laytonjb at charter.net (Jeffrey B. Layton)]

> Hi everyone,
>
> I forgot the root password for my fileserver machine (which runs
> FC2), so I booted it into Knoppix to "fix" /etc/shadow.  The fileserver's
> /etc is on a RAID1 device, /dev/md0, so I manually assembled the
> array using "mdadm" and mounted it. I was then able to reset the
> root password.
>
> However, as soon as I mounted /dev/md0, I noticed that the machine
> got really sluggish.  I ran "top", and saw that md0_raid1 is taking
> about 50% of the CPU, with md0_resync a close second at about
> 20%.  I left the machine booted into Knoppix overnight, with /md0
> mounted, thinking that maybe it was doing some kind of RAID magic,
> but ten hours later those tasks are still sucking down most of my
> CPU cycles.  Surely this is not expected behavior?
>
> -- JK
>   

How big is the RAID-1 file system? Also, is the machine swapping?

Jeff