From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Snitzer Date: Mon, 15 Mar 2010 18:01:37 -0400 Subject: lv-shared In-Reply-To: References: <20100315192925.GA29389@redhat.com> Message-ID: <20100315220136.GA3461@redhat.com> List-Id: To: lvm-devel@redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Mon, Mar 15 2010 at 4:06pm -0400, Mikulas Patocka wrote: > On Mon, 15 Mar 2010, Mike Snitzer wrote: > > > On Mon, Mar 15 2010 at 3:00pm -0400, > > Mikulas Patocka wrote: > > > > > Hi > > > > > > Why did you hide the "lv-shared" volume? With this hidden, the size and > > > percentage can't be seen. > > > > You can still see it with: lvs -a > > > > I'll have to revisit why I made it hidden (aside from the fact that the > > associated DM device is also hidden). There was some subtle reason that > > had to do with the refactoring of associations when I eliminated the > > distinct ->shared_snapshot pointer (otherwise the vg_validate() method > > would fail). > > I know it can be seen with lvs -a, but I think it's inconvenient for the > admin: > - the admin won't see that there is a shared store taking up space > - the admin won't see that the origin is a shared snapshot, he sees 'o', > but nothing that refers to that 'o' > - the percentage usage of the shared snapshot is hidden > > I think this information is important and should be displayed with plain > "lvs" command without any flags. (for example, the percentage usage is > critical, because it can overflow) --- so "lv-shared" shouldn't be hidden. Sure, not a problem. I've updated the relevant patch, see: http://people.redhat.com/msnitzer/patches/multisnap/lvm2/LVM2-2.02.62/lvm-shared-eliminate-shared_snapshot-in-lv.patch The lib/metadata/metadata.c:snapshot_count() changes in this updated patch address the vg_validate() issue I was seeing. The -shared cow was considered to be a normal "snapshot"; as such the vg_validate() checks failed. Mike