From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anssi Hannula Subject: Re: Recovery speed at 1MB/s/device, unable to change Date: Mon, 24 Apr 2006 01:48:39 +0300 Message-ID: <444C0447.4040200@gmail.com> References: <444BD3E7.4090601@gmail.com> <444BF3AC.4090804@gmail.com> <17483.63636.745420.456281@cse.unsw.edu.au> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <17483.63636.745420.456281@cse.unsw.edu.au> Sender: linux-raid-owner@vger.kernel.org To: Neil Brown Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids (sorry, prev post missed the list) Neil Brown wrote: > On Monday April 24, anssi.hannula@gmail.com wrote: > >># mdadm --grow /dev/md_d1 --raid-devices=3 --backup-file backupfile >>mdadm: Need to backup 128K of critical section.. >>mdadm: /dev/md_d1: Cannot get array details from sysfs >> >>Strace shows that it's trying to access >>"/sys/block/md_d4/md/component_size". >> >>Why is this? > > > Because I didn't test my code properly :-( > > Following patch should fix it. Okay, will test. > Re: the recovery speed problem: I would try dding from one drive to > the other and see what sort of speed you get then: > dd if=/dev/sda of=/dev/sdb bs=1024k count=1000 > or something like that. # export LANGUAGE=C; export LANG=C; export LC_ALL=C; date; dd if=/dev/sda skip=20000 of=/dev/sdb bs=1024k count=1000; date Mon Apr 24 01:14:48 EEST 2006 1000+0 records in 1000+0 records out Mon Apr 24 01:15:42 EEST 2006 So the speed is about 20MB/s. -- Anssi Hannula