From mboxrd@z Thu Jan 1 00:00:00 1970 From: Carsten Aulbert Subject: Re: RAID performance Date: Thu, 07 Feb 2013 11:29:26 +0100 Message-ID: <51138206.5000301@aei.mpg.de> References: <51134E43.7090508@websitemanagers.com.au> <5113516C.5080606@aei.mpg.de> <51137DFA.5020406@websitemanagers.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <51137DFA.5020406@websitemanagers.com.au> Sender: linux-raid-owner@vger.kernel.org To: Adam Goryachev Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids Hi On 02/07/2013 11:12 AM, Adam Goryachev wrote: > Do you have any information on what your workload is, or how/why these > values might help? Most of our data servers are exporting data read-only via NFS. It helped well on these but more on download servers which allowed us to go from 200k 4MB downloads per day to 1M/day while adding new files constantly. > > You are changing values significantly from the default, and I am > cautious that they may cause other issues. Also, someone else has > advised to reduce nr_requests rather than increasing it? > I know, but these larger queues really helped a lot in re-ordering requests to better match the hardware underneath - but again, this was for hard drives with physical arms and not SSDs Cheers Carsten -- Dr. Carsten Aulbert - Max Planck Institute for Gravitational Physics Callinstrasse 38, 30167 Hannover, Germany phone/fax: +49 511 762-17185 / -17193 https://wiki.atlas.aei.uni-hannover.de/foswiki/bin/view/ATLAS/WebHome