From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brad Campbell Subject: Re: 3.12: raid-1 mismatch_cnt question Date: Tue, 12 Nov 2013 08:39:20 +0800 Message-ID: <528178B8.4000704@fnarfbargle.com> References: <000f01ced948$2fbab140$8f3013c0$@lucidpixels.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Justin Piszcz , open list , linux-raid@vger.kernel.org List-Id: linux-raid.ids On 11/07/2013 06:54 PM, Justin Piszcz wrote: > On Mon, Nov 4, 2013 at 5:25 AM, Justin Piszcz wrote: >> Hi, >> >> I run two SSDs in a RAID-1 configuration and I have a swap partition on a >> third SSD. Over time, the mismatch_cnt between the two devices grows higher >> and higher. >> Are both SSD's identical? Do you have discard enabled on the filesystem? The reason I ask is I have a RAID10 comprised of 3 Intel and 3 Samsung SSD's. The Intel return 0 after TRIM while the Samsung don't, so I _always_ have a massive mismatch_cnt after I run fstrim. I never use a repair operation as it's just going to re-write the already trimmed sectors. Just a thought.