From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: TRIM support in drivers and dm/md? Date: Thu, 04 Nov 2010 12:45:33 -0400 Message-ID: <4CD2E32D.9030303@garzik.org> References: <4CD2B2EF.4050005@att.net> <20101104134014.GB21931@parisc-linux.org> <4CD2C755.3000908@att.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Matthew Wilcox , linux-fsdevel@vger.kernel.org To: Jeff Layton Return-path: Received: from mail-gy0-f174.google.com ([209.85.160.174]:46952 "EHLO mail-gy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751466Ab0KDQpi (ORCPT ); Thu, 4 Nov 2010 12:45:38 -0400 Received: by gyh4 with SMTP id 4so1542377gyh.19 for ; Thu, 04 Nov 2010 09:45:37 -0700 (PDT) In-Reply-To: <4CD2C755.3000908@att.net> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On 11/04/2010 10:46 AM, Jeff Layton wrote: > On 11/04/2010 09:40 AM, Matthew Wilcox wrote: >> On Thu, Nov 04, 2010 at 09:19:43AM -0400, Jeff Layton wrote: >>> Do many of the SATA controllers support TRIM? (i.e. pass >>> the TRIM command to the SSD). Does anyone know >>> anything about dm/md supporting TRIM? (I'm thinking LVM >>> and software RAID tools). >> As far as I know, there's nothing to be done in any SATA controller >> driver to support TRIM. It's just up to the drive whether it understands >> the command. > That's the rub. I've heard that many drivers don't understand > the command. So I'm curious what drivers do and any experience > anyone might have. Note the distinction between "drive" and "driver"... I agree with what Matthew says. Jeff