From mboxrd@z Thu Jan 1 00:00:00 1970 From: Harald Nikolisin Subject: Fwd: Re: Device utilization with RAID-1 Date: Thu, 18 Aug 2011 02:26:17 +0200 Message-ID: <4E4C5C29.6040303@googlemail.com> Reply-To: hochglanz@googlemail.com Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids hi, I didn't want to complain in general about SW RAID-1 performance. I simply think something is wrong with my setup and I have currently no idea how to improve. The basic questions (where I did not find an answer, neither in FAQ's nor in forum discussions) are. a) Is it normal that the hard drives show an permanent utilization (around 20%) without any noticeable actions on the computer? b) Should (as long as no resync happens) the state of mdadm active or clean? cheers, harald well, I have only 2 hard drives and no space for more.. Am 16.08.2011 03:29, schrieb Roberto Spadim: > try raid10 far layout > > 2011/8/15 Harald Nikolisin > > > Since a long time I'm unhappy with the performance of my RAID-1 system. > Investigation with atop and iostat unveils that the disk utilization is > always on a certain level although nothing happens on the system. In the > case of reading or writing files the utilization boosts always to 100% > for a long time. Very ugly examples are "Firefox starting" or "zypper > updates". > That is snapshot of the output of iostat: > > > Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s > avgrq-sz avgqu-sz await svctm %util > sda 0,00 0,00 0,00 7,33 0,00 43,33 > 5,91 0,33 43,18 33,32 24,43 > sdb 0,00 0,00 0,00 7,33 0,00 43,33 > 5,91 0,35 45,59 39,73 29,13 > md0 0,00 0,00 0,00 0,67 0,00 5,33 > 8,00 0,00 0,00 0,00 0,00 > md1 0,00 0,00 0,00 0,33 0,00 5,33 > 16,00 0,00 0,00 0,00 0,00 > md2 0,00 0,00 0,00 0,33 0,00 1,00 > 3,00 0,00 0,00 0,00 0,00 > md3 0,00 0,00 0,00 0,00 0,00 0,00 > 0,00 0,00 0,00 0,00 0,00 > md4 0,00 0,00 0,00 0,00 0,00 0,00 > 0,00 0,00 0,00 0,00 0,00 > md5 0,00 0,00 0,00 0,33 0,00 0,67 > 2,00 0,00 0,00 0,00 0,00 > > I checked with mdadm if a resync happens or so, but this is not the > case. The state says "active" on all RAID devices - btw. what is the > difference to "clean" ? > > thanks for any hints, > harald > -- > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > > > > -- > Roberto Spadim > Spadim Technology / SPAEmpresarial