From mboxrd@z Thu Jan 1 00:00:00 1970 From: pg@lxra2.for.sabi.co.UK (Peter Grandi) Subject: Re: RAID5 Performance Date: Thu, 28 Jul 2016 18:45:46 +0100 Message-ID: <22426.17610.799702.846715@tree.ty.sabi.co.uk> References: <7b7d730f-2951-ba5f-7f6b-33624b59a02d@websitemanagers.com.au> <7af0cc98-e395-9446-05eb-a6c0ca20f187@websitemanagers.com.au> <0eee845d-b833-0a92-8fe6-a2522218a0e6@websitemanagers.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <0eee845d-b833-0a92-8fe6-a2522218a0e6@websitemanagers.com.au> Sender: linux-raid-owner@vger.kernel.org To: Linux RAID List-Id: linux-raid.ids [ ... ] > My concern is that even if I solve *this* bottleneck (ie, the > 530 model SSD being too busy), that there will be another > bottleneck afterwards There is always another bottleneck ;-). [ ... ] > I'm not sure, but I think I've had one of the 480GB drives > fail, and 3 of the smaller 60GB and 80GB drives fail. So far, > only the 480G failure was "catastrophic", the others were > still operating . All were replaced by Intel. [ ... ] When flash SSD drives run over their "expected" write amount they behave differently: http://www.sabi.co.uk/blog/15-one.html#150406b Intel flash SSDs apparently do the following: * They switch immediately to read-only. * On the next power up they refuse even to *read*. BTW, as to the Samsung SM863 there is a relatively recent "group test" here: http://www.storagereview.com/samsung_sm863_ssd_review The average and max latency graphs are interesting, especially those under "Preconditioning Curve".