From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: Curious problem with asynchronous RAID1 rebuild operations Date: Tue, 5 Jul 2011 10:34:04 +1000 Message-ID: <20110705103404.0ed0e9bb@notabene.brown> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: "Cal Leeming [Simplicity Media Ltd]" Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On Sat, 2 Jul 2011 12:07:54 +0100 "Cal Leeming [Simplicity Media Ltd]" wrote: > Hi all, >=20 > I tried to rebuild/sync two RAID1 arrays at the same time, with stran= ge results. >=20 > When a new drive was added into md0, it started to sync fine at > 123,000kb/sec. Whilst that was running, I also added a new drive into > md1, and this causes both arrays sync speed to slow down to > 20,000kb/sec. I checked the=A0/proc/sys/dev/raid/speed_limit_{min|max= } > and these were both set fine. >=20 > I removed the drive from md1, and the md0 sync went back to the norma= l speed. >=20 > RAID Setup: > md0 - 2 drives (2TB Western Digital) > md1 - 2 drives (500GB M3 SDD) >=20 > So my question is, does anyone know why the sync speed (on all arrays= ) > slowed down to almost 6-7 times the norm, when two (or more?) sync > operations are taking place? >=20 Dodgy controller? I assume both arrays are on the same controller. Can you plug in a separate controller even if only temporarily and see = what happens? I can see how any interaction with md would have this effect. NeilBrown -- To unsubscribe from this list: send the line "unsubscribe linux-raid" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html