Re: [CentOS] Strange performance issue on CentOS 6.7 server

2016-02-04 Thread Warren Young
On Feb 3, 2016, at 3:23 PM, Alfred von Campe wrote: > > On Feb 3, 2016, at 17:10, Warren Young wrote: > >> smartctl can see through several different types of RAID controller to the >> underlying physical disks via its -d option. > > This is what I have: > > # smartctl --all /dev/sda > smartc

Re: [CentOS] Strange performance issue on CentOS 6.7 server

2016-02-03 Thread James Hogarth
On 3 Feb 2016 22:24, "Alfred von Campe" wrote: > > On Feb 3, 2016, at 17:10, Warren Young wrote: > > > smartctl can see through several different types of RAID controller to the underlying physical disks via its -d option. > > This is what I have: > > # smartctl --all /dev/sda > smartctl 5.43 2012

Re: [CentOS] Strange performance issue on CentOS 6.7 server

2016-02-03 Thread Alfred von Campe
On Feb 3, 2016, at 17:10, Warren Young wrote: > smartctl can see through several different types of RAID controller to the > underlying physical disks via its -d option. This is what I have: # smartctl --all /dev/sda smartctl 5.43 2012-06-30 r3573 [i686-linux-2.6.32-573.12.1.el6.i686] (local b

Re: [CentOS] Strange performance issue on CentOS 6.7 server

2016-02-03 Thread Warren Young
On Feb 3, 2016, at 2:26 PM, 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 t

Re: [CentOS] Strange performance issue on CentOS 6.7 server

2016-02-03 Thread m . roth
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 >> r

Re: [CentOS] Strange performance issue on CentOS 6.7 server

2016-02-03 Thread Alfred von Campe
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 reallly > sow. > > You can

Re: [CentOS] Strange performance issue on CentOS 6.7 server

2016-02-03 Thread Warren Young
On Feb 3, 2016, at 1:30 PM, Alfred von Campe 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 t