From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?B?S2Fyc3RlbiBSw7Zta2U=?= Subject: Re: misunderstanding of spare and raid devices? - and one question more Date: Sat, 02 Jul 2011 10:34:30 +0200 Message-ID: <4E0ED816.30903@gmx.de> References: <4E0C5539.4030000@gmx.de> <4E0C5E47.5090604@anonymous.org.uk> <4E0C6CC4.3030506@turmel.org> <4E0C7196.1070307@gmx.de> <4E0C7B4B.7090404@turmel.org> <4E0C8685.3020806@gmx.de> <4E0C8BD6.1080907@turmel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4E0C8BD6.1080907@turmel.org> Sender: linux-raid-owner@vger.kernel.org To: Phil Turmel Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids Hi Phil, I have done some tests and appended the results, maybe they are of interest for somebody. As a conclusion I would say raid5 and raid6 make in my situation nearly no difference. Thanks to all for hints and explanation Karsten -------------------------------------------------------------------------------------- first - just copy a dir with a size of 2,9 GB, it was copied once before so I think there are still data buffered? OLDER war im Cache? hatte Dir vorher kopiert kspace9:~ # date ; cp -a /home/roemke/HHertzTex/OLDER/* /raid5/ ; date Fr 1. Jul 16:15:57 CEST 2011 Fr 1. Jul 16:16:26 CEST 2011 kspace9:~ # date ; cp -a /home/roemke/HHertzTex/OLDER/* /raid6/ ; date Fr 1. Jul 16:17:27 CEST 2011 Fr 1. Jul 16:17:58 CEST 2011 -------------------------------------------------------------------------------------- now a test with bonnie, I found this example online and the parameters seems senseful to me (I've never done performance tests on hd's before, so I searched for an example) bonnie, found -n 0 : file creation 0 -u 0 : root -r : memory in megabyte (calculated to 7999) -s : file size calculated to 15998 -f : fast, skip per char IO-tests -b : no write buffering -d : set directory kspace9:~ # bonnie++ -n 0 -u 0 -r `free -m | grep 'Mem:' | awk '{print $2}'` -s $(echo "scale=0;`free -m | grep 'Mem:' | awk '{print $2}'`*2" | bc -l) -f -b -d /raid5 Using uid:0, gid:0. Writing intelligently...done Rewriting...done Reading intelligently...done start 'em...done...done...done... Version 1.03d ------Sequential Output------ --Sequential Input- --Random- -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks-- Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP kspace9 15998M 96365 20 48302 12 149445 18 113.7 0 kspace9,15998M,,,96365,20,48302,12,,,149445,18,113.7,0,,,,,,,,,,,,, kspace9:~ # bonnie++ -n 0 -u 0 -r `free -m | grep 'Mem:' | awk '{print $2}'` -s $(echo "scale=0;`free -m | grep 'Mem:' | awk '{print $2}'`*2" | bc -l) -f -b -d /raid6 Using uid:0, gid:0. Writing intelligently...done Rewriting...done Reading intelligently...done start 'em...done...done...done... Version 1.03d ------Sequential Output------ --Sequential Input- --Random- -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks-- Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP kspace9 15998M 100321 22 48617 13 131651 16 120.2 1 kspace9,15998M,,,100321,22,48617,13,,,131651,16,120.2,1,,,,,,,,,,,,, =================================================================================== results for old raid 1: a test of old raid 1 which I have done unintended, because I forgot to mount the raid array :-) mounten vergessen --------------------------------------------------------------------- -> vergleichsresultate :-) kspace9:~ # date ; cp -r /home/roemke/HHertzTex/OLDER/ /raid5/ ; date Fr 1. Jul 16:07:32 CEST 2011 ^^^ not raid 5, old raid 1, forgot to mount Fr 1. Jul 16:08:39 CEST 2011 aehnlich (similiar) test mit bonnie++ kspace9:~ # bonnie++ -n 0 -u 0 -r `free -m | grep 'Mem:' | awk '{print $2}'` -s $(echo "scale=0;`free -m | grep 'Mem:' | awk '{print $2}'`*2" | bc -l) -f -b -d /raid5 <-- not raid 5, still the older raid 1 Using uid:0, gid:0. Writing intelligently...done Rewriting...done Reading intelligently...done start 'em...done...done...done... Version 1.03d ------Sequential Output------ --Sequential Input- --Random- -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks-- Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP kspace9 15998M 62977 9 34410 9 101979 13 66.7 0 kspace9,15998M,,,62977,9,34410,9,,,101979,13,66.7,0,,,,,,,,,,,,,