From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from wnls-smtp3.wa.co.za ([41.185.62.208]:6708 "EHLO wnls-smtp3.wa.co.za" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751032Ab3ASVO3 (ORCPT ); Sat, 19 Jan 2013 16:14:29 -0500 Message-ID: <50FB0CA1.4070204@swiftspirit.co.za> Date: Sat, 19 Jan 2013 23:14:09 +0200 From: Brendan Hide MIME-Version: 1.0 To: Gene Czarcinski CC: linux-btrfs@vger.kernel.org, Josef Bacik Subject: Re: [PATCH 6/6] Btrfs-progs: detect if the disk we are formatting is a ssd References: <1358618781-26629-1-git-send-email-gene@czarc.net> <1358618781-26629-7-git-send-email-gene@czarc.net> In-Reply-To: <1358618781-26629-7-git-send-email-gene@czarc.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: 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 ... :-/ -- Brendan Hide http://swiftspirit.co.za/