[CentOS] Drive problem

Tue Jun 16 20:56:43 UTC 2015
Valeri Galtsev <galtsev at kicp.uchicago.edu>

On Tue, June 16, 2015 1:23 pm, m.roth at 5-cent.us wrote:
> Valeri Galtsev wrote:
>> On Tue, June 16, 2015 7:11 am, mark wrote:
>>> On 06/16/15 07:59, Ashish Yadav wrote:
>>>> Hi,
>>>> On Tue, Jun 16, 2015 at 2:26 AM, <m.roth at 5-cent.us> wrote:
>>>>> I was rsync'ing data from one system to another, and the recipient
>>>>> suddenly started throwing DRDY errors. Now, it's a fairly new WD Red
>>>>> 3TB, and I'd think it was just a bad drive... but I'm really
>>>>> confused by this, from the logs:
>>>>> Jun 15 15:34:43 <servername> kernel: ata3: SError: { Dispar }
>>>>> Dispar? And googling, every reference I find to that word always has
>>>>> something else there.
>>>>> System's running 5.11. Filesystem's xfs.
>>>>> Any thoughts?
>>>> Please check your SATA data cable first, I have similar experience
>>>> where something was wrong with the cable and it started to give
>>>> DRDY errors. When I put that disk into another machine then
>>>> it was working fine without any problem.
>>> It's something to consider... but I can't do that easily. This is a
>>> server that's been running for years, and is in use, and it's a
>>> hot-swap bay.
>> Then it also could be caused by a micro crack on a backplane.
> It was working fine before I put in the 3TB drive earlier this year, and I
> haven't had any trouble at all with it until yesterday, when I started
> copying a lot of data to a not-much-used disk.

Then I would agree, cable is much more like reason than (microcrack in)
backplane. Cable may have just marginally insufficient bandwidth, whereas
microcrack effect is usually (but not always) "more fatal".

Does drive plug in into connector nice and smoothly, and tray moves into
hotswap bay smoothly? When you plug the drive, you usually can feel when
connector plugs in, and drive usually moved further in more than 1/16 of
an inch (or more than 2 mm). This is usually sufficient for good

How about sticking drive into different machine and trying to mount
filesystem there? Any Linux workstation you have around may do.

The last of wild guesses: could it be that the PS of the box in question
is marginally insufficient in power? This tends to show up on machines
that run well for years even if you didn't change anything, and the reason
maybe one of two: electrolytic capacitor loose to some extent their
capacitance with age, and hard drive with age start drawing more power.
Could your new big drive push your box in that direction?

Good luck!


Valeri Galtsev
Sr System Administrator
Department of Astronomy and Astrophysics
Kavli Institute for Cosmological Physics
University of Chicago
Phone: 773-702-4247