[CentOS] Strange performance issue on CentOS 6.7 server

Alfred von Campe wrote:
> On Feb 3, 2016, at 16:13, Warren Young wrote:
>
>> A dying hard disk can do it.  HDDs try to silently paper over I/O
>> errors, but what they can’t hide is the time it takes to do this.  If
>> your HDD is constantly correcting errors at the oxide layer, it will be
>> reeeeeallly sllllow.
>>
>> You can try running SMART tests on it, though that’s not guaranteed to
>> show the problem.
>
> Well, it’s not “a” disk: it’s a HW RAID of about dozen (server grade)
> drives, with a VG/LV on top of that.  Are there any log files I can check
> that test the underlying VG/LV health status?
>
You don't mention what kind of h/w RAID. LSI-based controller, and
HP-based ones, both have utilities to check out the drives (MegaRAID and
hpacli, respectively); AC&NC JetStors have a web interface.

    mark