From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joe Thornber Subject: Re: dm thin: relax hard limit on the maximum size of a metadata device Date: Tue, 6 Mar 2012 10:09:53 +0000 Message-ID: <20120306100952.GA5323@ubuntu> References: <1330723953-16872-1-git-send-email-snitzer@redhat.com> <20120305102133.GB6431@ubuntu> <20120305140421.GA25562@redhat.com> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20120305140421.GA25562@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: Mike Snitzer Cc: dm-devel@redhat.com, ejt@redhat.com List-Id: dm-devel.ids On Mon, Mar 05, 2012 at 09:04:21AM -0500, Mike Snitzer wrote: > On Mon, Mar 05 2012 at 5:21am -0500, > Joe Thornber wrote: > > > Hi Mike, > > > > My concerns are: > > > > i) The current behaviour is upstream; by changing this aren't you > > making the tools writers life more complicated rather than less by > > making them support both interfaces? > > It is an incremental improvement. Allows the kernel to be forgiving. > How does this impact some tool that took the special care to limit the > size of the device to METADATA_DEV_MAX_SECTORS (which is < 16G)? You're making this change to make life easier for tool writers, yet tool writers still have to support the existing 3.2 kernel and deal with the 16G limit. > Whatever the tools may be doing is not my concern. Ideally the users > and tool authors understand that 16G is insane for thinp metadata. But > in the event that they use 16G would you rather we reject them? Yes, I would rather reject, than let people think they had 32G of metadata. It also forces the tool writers to do something sane. I don't feel strongly enough about this to keep arguing. So consider this an ACK and see if you can get it past Alasdair. - Joe