[CentOS] Strange performance issue on CentOS 6.7 server

On Feb 3, 2016, at 1:30 PM, Alfred von Campe <alfred at von-campe.com> wrote:
> 
> I suspected that file I/O might be slow, and sure enough, that appears to be the case….What could cause this

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.

Got tested backups? :)