[CentOS] Filesystem writes unexpectedly slow (CentOS 6.4)

Tue Oct 14 02:16:07 UTC 2014
Peter <peter at pajamian.dhs.org>

On 10/14/2014 02:15 PM, Joakim Ziegler wrote:
> I have a rather large box (2x8-core Xeon, 96GB RAM) where I have a
> couple of disk arrays connected on an Areca controller. I just added a
> new external array, 8 3TB drives in RAID5, and the testing I'm doing
> right now is on this array, but this seems to be a problem on this
> machine in general, on all file systems (even, possibly, NFS, but I'm
> not sure about that one yet).

The first thing I would check is that you have a BBU installed on the
areca controller and that it is functioning properly (check the cli, I
don't know the exact commands off the top of my head), also make sure
that write caching is enabled on the controller (after you've checked
the BBU, of course).  Without a working BBU in place hardware RAID
controllers, such as areca, disable write caching (by default) and this
will have a significant impact on write speeds.

Note that newer controllers use a type of flash memory instead of a BBU.


Peter