From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guy Martin Subject: Re: Raid 5 to raid 6 reshape failure after reboot Date: Thu, 22 Oct 2009 16:20:29 +0200 Message-ID: <20091022162029.0cc2a1aa@zombie> References: <20091018181033.0255346c@borg.bxl.tuxicoman.be> <358606dfd356518f7fa42219f26082d2.squirrel@neil.brown.name> <20091019155322.65b4287f@zombie> <5744c797713398f21b00e5323ddeac1e.squirrel@neil.brown.name> <20091020103731.5dc611ff@zombie> <19167.40181.250468.925659@notabene.brown> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <19167.40181.250468.925659@notabene.brown> Sender: linux-raid-owner@vger.kernel.org To: Neil Brown Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids Neil, While redoing the reboot test, I've also noticed this : When I first issue the --grow command, I see the following in dmesg : [192752.106467] md: reshape of RAID array md0 [192752.106473] md: minimum _guaranteed_ speed: 200000 KB/sec/disk. [192752.106479] md: using maximum available idle IO bandwidth (but not more than 200000 KB/sec) for reshape. The minimum guaranteed speed should be 1000KB/sec according to the entry in /proc/sys/dev/raid/speed_limit_min. Also, the performances are not really good. I have about 400K/sec according to /proc/mdstat. Now, if I stop the array and assemble it again, things are better. The output in dmesg displays the correct value : [193138.646204] md: minimum _guaranteed_ speed: 1000 KB/sec/disk. [193138.646210] md: using maximum available idle IO bandwidth (but not more than 200000 KB/sec) for reshape. And perf are much better, I now get ~1500K/s which shrinks the time of the reshape from ~2 weeks to 'only' a few days. Any thoughts ? HTH, Guy On Thu, 22 Oct 2009 10:44:53 +1100 Neil Brown wrote: > Thanks for helping make mdadm even better! > > NeilBrown >