From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Martin K. Petersen" Subject: Re: [PATCH] raid0: data corruption when using trim Date: Thu, 23 Jul 2015 18:17:18 -0400 Message-ID: References: <013e01d0c1d2$f3af4fb0$db0def10$@samsung.com> <20150720173830.GA3274@lazy.lzy> <20150720183402.GA4439@lazy.lzy> <55B11A68.4080706@assyoma.it> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <55B11A68.4080706@assyoma.it> (Gionatan Danti's message of "Thu, 23 Jul 2015 18:46:32 +0200") Sender: linux-raid-owner@vger.kernel.org To: Gionatan Danti Cc: "Martin K. Petersen" , Piergiorgio Sartor , Seunguk Shin , neilb@suse.de, linux-raid@vger.kernel.org List-Id: linux-raid.ids >>>>> "Gionatan" == Gionatan Danti writes: Gionatan> I *think* that, as this TRIM command is processed way above Gionatan> the ATA layer (it is processed inside the device-mapper code), Gionatan> the bug should not happen here. Is it correct? Are we safe Gionatan> with ThinLVM + MDRAID10 + HDDs? The problem only occurs if you are using MD linear/raid0/raid10 on top of a device that implements either DSM TRIM (SATA) or UNMAP (SCSI). If the device prefers WRITE SAME w/ UNMAP or if it does not support discards at all there is no problem. -- Martin K. Petersen Oracle Linux Engineering