From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brad Campbell Subject: Add drives and restripe performance Date: Fri, 08 Aug 2014 11:36:39 +0800 Message-ID: <53E445C7.8030909@fnarfbargle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids G'day all, We don't see a lot of speed/time estimates float past so I thought I'd put this out there for anyone contemplating this sort of thing. I have a RAID 6 now comprised of 14 2TB drives (WD Green and Red). The drives are connected via 3 LSI SAS2008 controllers and each on a single channel. On a good day I can get 7-800Mb/s to or from the array, so streaming performance is excellent. It took approximately a day (+/-) to grow the array from 12 drives to 14. It has taken approximately 10 days to re-stripe from 128k chunks to 64k chunks with the backup file on a RAID-10 of SSD's (its not finished but I'm about 8 hours away). Both of these operations were performed with the array as idle as was practical (all common users of the array were stopped). Based on the grow performance I had banked on about a week for the restripe so I wasn't massively far out in my estimation. If the array was under regular use then the estimate for the restripe was more like a month. I had to stop the SMART daemon as the morning run of SMART tests was causing the estimate to blow out to a month while the tests were active, and the normally 90 minute tests were taking 18 hours. Still much nicer than a 24TB backup/recreate/restore.