From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCHSET] block,scsi,libata: implement alt_size Date: Mon, 04 May 2009 17:02:47 +0900 Message-ID: <49FEA127.1000905@kernel.org> References: <1233456951-992-1-git-send-email-tj@kernel.org> <49F902CF.7080307@garzik.org> <49F903DD.8040707@kernel.org> <49FA0349.3090706@garzik.org> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: Dan Williams Cc: Jeff Garzik , linux-scsi@vger.kernel.org, Mauelshagen@redhat.com, linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org, dm-devel@redhat.com, jens.axboe@oracle.com List-Id: linux-ide@vger.kernel.org Dan Williams wrote: > On Thu, Apr 30, 2009 at 1:00 PM, Jeff Garzik wrote: >> Tejun Heo wrote: >>> Hello, >>> >>> Jeff Garzik wrote: >>>> I suppose... >>>> >>>> It just seems like a nasty hack, but unfortunately I don't see >>>> anyone stepping up to do it properly -- with a DM device >>>> automatically layered on top that splits the device into separate >>>> regions: one block device for the 'regular' area, and one for the >>>> HPA. >>> Isn't that more hacky? I don't know. All that dm needs to know is >>> the location of the metadata which is located w.r.t. the end of the >>> device which might be at a different location if BIOS tried to pull >>> silly stunts. So, exporting the size BIOS might have used seems like >>> a straight forward solution to me. >> " I suppose" is basically a reluctant ack, in the absence of other >> solutions :) >> > > Couldn't the "fix" also just be a note to users to disable ignore_hpa > if they notice that there raid arrays are not assembling correctly? I don't know. If it doesn't work automatically, the solution really isn't worth much. People generally don't (shouldn't need to) have any idea what HPA is. It basically boils down to "Linux doesn't support RAID". :-) Maybe we should just put this issue to the rest and strongly advise people against BIOS raids. Thanks. -- tejun