From mboxrd@z Thu Jan 1 00:00:00 1970 From: Phil Turmel Subject: Re: Raid stalls during --replace and other disk activity... Date: Sat, 15 Mar 2014 15:19:05 -0400 Message-ID: <5324A7A9.1040700@turmel.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Scott D'Vileskis , linux-raid@vger.kernel.org List-Id: linux-raid.ids On 03/15/2014 12:28 AM, Scott D'Vileskis wrote: > However, when I started a format of an unrelated partition on > /dev/sda, the RAID 'recovery' disk-replacement completely stopped. I > suspect the RAID rebuild mechanism is pausing because of the activity > on /dev/sda. > > I monkeyed with > echo 90000 > speed_limit_min > and now I get 10 second bursts of 20-100MB/sec every 30 seconds or so, > so at least the jobs will finish in parallel.. > > I feel the RAID --replace option should only concern itself with the > two disks involved not get caught up because of activity on another > disk. Is this a bug? This is deliberate, and in my opinion, desirable. Same thing happens when doing a check or any kind of rebuild on multiple arrays that use partitions on shared underlying devices. If you don't limit the raid background activity, the extra seek load on the devices can severely cut performance, especially on spinning rust. Phil