From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bill Davidsen Subject: Re: Need to remove failed disk from RAID5 array Date: Thu, 19 Jul 2012 10:25:25 -0400 Message-ID: <500818D5.4080208@tmr.com> References: <50071C0A.8080307@tmr.com> <20120719091611.22e16100@natsu> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20120719091611.22e16100@natsu> Sender: linux-raid-owner@vger.kernel.org To: Roman Mamedov Cc: Alex , Linux RAID , Neil Brown List-Id: linux-raid.ids Roman Mamedov wrote: > On Wed, 18 Jul 2012 22:44:06 -0400 > Alex wrote: > >> I'm not sure what stats I could provide to troubleshoot this further. >> At this rate, the 2.7T array will take a full day to resync. Is that >> to be expected? > 1) did you try increasing stripe_cache_size? > > 2) maybe it's an "Advanced Format" drive, the RAID partition is not properly > aligned? > That's a good argument for not using "whole disk" array members, a partition can be started at a good offset and may perform better. As for the speed, since it is reconstructing the array data (hope the other drives are okay), every block written requires three blocks read and a reconstruct in cpu and memory. You can use "blockdev" to increase readahead, and set the devices to use the deadline scheduler, that _may_ improve things somewhat, but you have to read three block to write one, so it's not going to be fast. -- Bill Davidsen We are not out of the woods yet, but we know the direction and have taken the first step. The steps are many, but finite in number, and if we persevere we will reach our destination. -me, 2010