[PLUG] Caution on RHEL 6 on Laptops

[MJang]

Folks, 

I know a number of people here run RHEL (or rebuilds such as CentOS) on
their systems -- wanted to share a problem I've apparently had on my
T410 / 500G hard drive since I installed RHEL 6. I reported it at
https://bugzilla.redhat.com/show_bug.cgi?id=667485 

Bottom line, I think a default RHEL 6 setting caused my hard drive to
fail in less than 2 months

-- adding 200,000 cycles in that time (as defined by the smartctl
-a /dev/sda | grep Load_Cycle_Count command)

When I ran normal recovery stuff on that drive, the problems were
essentially limited to the partition with the RHEL 6 top-level root
directory.

If I understand correctly, 200,000 cycles shouldn't by itself cause a
drive failure, but I'm guessing the way the cycles were focused on hte
RHEL 6 partition contributed to the failure. Perhaps I'm
misunderstanding something about hdparm and cycles, I don't know.

I think a similar bug for Ubuntu was discussed here a while back, which
I cited in the bugzilla.

I've read some stuff that suggests the problem might be limited to
certain hard drives (e.g. Hitachi), and is a problem on laptops because
of power save schemes.

Since I installed a new drive, I've had some success reducing the number
of cycles with each of the following commands:

hdparm -B 200 /dev/sda
hdparm -B 254 /dev/sda

Not sure which is better, but if you have RHEL 6 or a rebuild on your
laptop, I'm guessing either should help.

Thanks,
Mike