From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934528AbdLRTLv (ORCPT ); Mon, 18 Dec 2017 14:11:51 -0500 Received: from merlin.infradead.org ([205.233.59.134]:43574 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933534AbdLRTLq (ORCPT ); Mon, 18 Dec 2017 14:11:46 -0500 Subject: Re: [PATCH v4 1/2] dm-unstripe: unstripe RAID 0/dm-striped device To: Scott Bauer , dm-devel@redhat.com Cc: snitzer@redhat.com, agk@redhat.com, linux-kernel@vger.kernel.org, keith.busch@intel.com, jonathan.derrick@intel.com References: <20171218172809.5826-1-scott.bauer@intel.com> <20171218172809.5826-2-scott.bauer@intel.com> From: Randy Dunlap Message-ID: Date: Mon, 18 Dec 2017 11:11:39 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.5.0 MIME-Version: 1.0 In-Reply-To: <20171218172809.5826-2-scott.bauer@intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/18/2017 09:28 AM, Scott Bauer wrote: > This device mapper module remaps and unstripes IO so it lands > solely on a single drive in a RAID 0/dm-stripe target. > In a 4 drive RAID 0 the mapper exposes 1/4th of the LBA range > as a virtual drive. Each IO to that virtual drive will land on > only one of the 4 drives, selected by the user. > > Signed-off-by: Scott Bauer > Acked-by: Keith Busch > --- > drivers/md/Kconfig | 10 +++ > drivers/md/Makefile | 1 + > drivers/md/dm-unstripe.c | 204 +++++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 215 insertions(+) > create mode 100644 drivers/md/dm-unstripe.c > > diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig > index 83b9362be09c..e1c48a7f98f1 100644 > --- a/drivers/md/Kconfig > +++ b/drivers/md/Kconfig > @@ -269,6 +269,16 @@ config DM_BIO_PRISON > > source "drivers/md/persistent-data/Kconfig" > > +config DM_UN_STRIPE > + tristate "Transpose IO to individual drives on a raid device" > + depends on BLK_DEV_DM > + ---help--- > + Enable this feature if you with to unstripe I/O on a RAID 0 > + device to the respective drive. If your hardware has physical > + RAID 0 this module can unstripe the I/O to respective sides. What does "sides" mean above? > + > + If unsure say N. > + thanks, -- ~Randy