From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cantor2.suse.de ([195.135.220.15]:53434 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752909Ab3AUNB3 (ORCPT ); Mon, 21 Jan 2013 08:01:29 -0500 Date: Mon, 21 Jan 2013 14:01:22 +0100 From: David Sterba To: Brendan Hide Cc: Gene Czarcinski , linux-btrfs@vger.kernel.org, Josef Bacik Subject: Re: [PATCH 6/6] Btrfs-progs: detect if the disk we are formatting is a ssd Message-ID: <20130121130122.GH19967@twin.jikos.cz> Reply-To: dsterba@suse.cz References: <1358618781-26629-1-git-send-email-gene@czarc.net> <1358618781-26629-7-git-send-email-gene@czarc.net> <50FB0CA1.4070204@swiftspirit.co.za> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <50FB0CA1.4070204@swiftspirit.co.za> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Sat, Jan 19, 2013 at 11:14:09PM +0200, Brendan Hide wrote: > On 2013/01/19 08:06 PM, Gene Czarcinski wrote: > >Signed-off-by: Josef Bacik > >Signed-off-by: Gene Czarcinski > >--- > >-values are raid0, raid1, raid10 or single. > >+values are raid0, raid1, raid10, single or dup. Single device will have dup > >+set by default except in the case of SSDs which will default to single. This is > >+because SSDs can remap blocks internally so duplicate blocks could end up in the > >+same erase block which negates the benefits of doing metadata duplication. > Can't help but suggest that a "NO_DEDUP" command could be added to the SATA > Transport Protocol/SCSI Command set. Not sure where to submit that idea ... > :-/ You might get your answer from lkml, fsdevel or linux-scsi. david