[CentOS] Disk Performance Issue

Tue Jun 25 00:27:39 UTC 2019
Jon LaBadie <jcu at labadie.us>

On Mon, Jun 24, 2019 at 03:42:24PM +0000, Chris Olson via CentOS wrote:
> We have a very old Dell desk top machine that has been running
> CentOS 6 for the past five years.  It received a new, 1 TB disk
> and additional memory before the OS installation.  It has been
> the primary Linux machine in our smallest and most remote field
> office.  It has been updated at least once a week and has all
> current dates installed.
> 
> Boot-up this morning lasted about six times as long as usual.
> Disk access, as indicated by the disk activity light, is almost
> continuous and for extended periods of time when ever something
> is done that requires the disk.  Everything observed happens
> whether or not the machine is connected to our network. All of
> our files appear to be accessible if one is patient.
> 
> One theory put forward is that some application is running that
> uses up CPU and disk bandwidth.  Another theory is that thereare disk errors, mostly corrected by EDCS features. We do not
> see any rogue applications and error logs show no disk issues.
> 
> This is a mysterious issue that we hope to circumvent by putting
> a new disk and installing CentOS 7 from DVD.  Our hope is that
> the current disk can be mounted externally on the new CentOS
> system using a USB to SATA adapter and that data can be moved
> off of the old disk. 
> 
> Advice regarding this issue and any possible diagnostic methods
> will be greatly appreciated.
> 
> df -k output:
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> Filesystem        1K-blocks      Used Available Use% Mounted on
> /dev/mapper/vg_delle520-lv_root
>                    51475068  12110896  36742732  25% /
> tmpfs               1928152       176   1927976   1% /dev/shm
> /dev/sda1            487652    211073    250979  46% /boot
> /dev/mapper/vg_delle520-lv_home
>                   905124888 246856176 612284356  29% /home
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 

If it had not been booted in a while, it may have been running
the file system check (fsck) program.  I think if fsck has not
been run in 6 months, it automatically happens at boot.

jl
-- 
Jon H. LaBadie                 jon at jgcomp.com
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