From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: Race to power off harming SATA SSDs Date: Mon, 8 May 2017 13:43:03 -0400 Message-ID: <20170508174303.GA12079@htj.duckdns.org> References: <1494228094.6528.14.camel@infradead.org> <1494231215.6528.22.camel@infradead.org> <1494233673.6528.28.camel@infradead.org> <7ee84982-cfad-94d7-4e22-4edbeb852b32@redhat.com> <1494238390.6528.42.camel@infradead.org> <20170508135005.0b9b200b@bbrezillon> <20170508164322.GA9781@amd> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20170508164322.GA9781@amd> Sender: linux-scsi-owner@vger.kernel.org To: Pavel Machek Cc: Boris Brezillon , David Woodhouse , Hans de Goede , Ricard Wanderlof , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org, linux-mtd@lists.infradead.org, Henrique de Moraes Holschuh List-Id: linux-ide@vger.kernel.org Hello, On Mon, May 08, 2017 at 06:43:22PM +0200, Pavel Machek wrote: > What I was trying to point out was that storage people try to treat > SSDs as HDDs... and SSDs are very different. Harddrives mostly survive > powerfails (with emergency parking), while it is very, very difficult > to make SSD survive random powerfail, and we have to make sure we > always powerdown SSDs "cleanly". We do. The issue raised is that some SSDs still increment the unexpected power loss count even after clean shutdown sequence and that the kernel should wait for some secs before powering off. We can do that for select devices but I want something more than "this SMART counter is getting incremented" before doing that. Thanks. -- tejun