From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Snitzer Date: Fri, 19 Mar 2010 15:39:08 -0400 Subject: lv-shared In-Reply-To: <20100315220136.GA3461@redhat.com> References: <20100315192925.GA29389@redhat.com> <20100315220136.GA3461@redhat.com> Message-ID: <20100319193908.GB7345@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 6:01pm -0400, Mike Snitzer wrote: > 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. Mikulas, I've cleaned up my patches that layer on your a bit, and updated to 2.02.63: http://people.redhat.com/msnitzer/patches/multisnap/lvm2/LVM2-2.02.63/ This patch saw some changes becuase I moved some functions around: http://people.redhat.com/msnitzer/patches/multisnap/lvm2/LVM2-2.02.63/lvm-shared-additional-wrappers.patch One fix associated with the changes is detailed at the end of the following patch's header: http://people.redhat.com/msnitzer/patches/multisnap/lvm2/LVM2-2.02.63/lvm-shared-eliminate-shared_snapshot-in-lv.patch And I implemented the ACCESS_HIDDEN_LV flag we talked about with this patch: http://people.redhat.com/msnitzer/patches/multisnap/lvm2/LVM2-2.02.63/lvm-shared-add-ACCESS_HIDDEN_LV-flag.patch With the result being: # lvs LV VG Attr LSize Origin Snap% Move Log Copy% Convert testlv1 test owi-a- 4.00g [testlv1-shared] test swi--- 1.00g testlv1 0.01 testlv1_snap test swi-a- 4.00g testlv1 Mike