On Fri, 07 Sep 2012 13:27:15 +0530, "M. Mohan Kumar" <mo...@in.ibm.com> wrote: > On Fri, 07 Sep 2012 09:35:10 +0300, Itamar Heim <ih...@redhat.com> wrote: > > On 09/07/2012 08:21 AM, M. Mohan Kumar wrote: > > > On Thu, 6 Sep 2012 18:59:19 -0400 (EDT), Ayal Baron <aba...@redhat.com> > > > wrote: > > >> > > >> > > > > > > > > For start using the LVs we will always do truncate for the required > > > size, it will resize the LV. I didn't get what you are mentioning about > > > thin-provisioning, but I have a dumb code using dm-thin targets showing > > > BD xlators can be extended to use dm-thin targets for thin-provisioning. > > > > so even though this is block storage, it will be extended as needed? how > > does that work exactly? > > say i have a VM with a 100GB disk. > > thin provisioning means we only allocated 1GB to it, then as the guest > > uses that storage, we allocate more as needed (lvextend, pause guest, > > lvrefresh, resume guest) > > > > > > When we use device=lv, it means we use only thick provisioned logical > volumes. If this logical volume runs out of space in the guest, one can > resize it from the client by using truncate (results in lvresize at the > server side) and run filesystem tools at guest to get added space. > > But with device=thin type, all LVs are thinly provisioned and allocating > space to them is taken care by device-mapper thin target > automatically. The thin-pool should have enough space to accomoodate the > sizing requirements. > As of now BD xlator supports only working with linear Logical volumes, they are thick provisioned. gluster cli command "gluster volume create" with option "device=lv" allows to work with logical volumes as files.
As a POC I have a code(not posted to external list), with option "device=thin" to gluster volume create command it allows to work with thin provisioned targets. But it does not take care of resizing thin-pool when it reaches low-level threshold. Supporting thin targets is in our TODO list. We have dependency on lvm2 library to provide apis to create thin-targets. _______________________________________________ vdsm-devel mailing list vdsm-devel@lists.fedorahosted.org https://lists.fedorahosted.org/mailman/listinfo/vdsm-devel
