* Andrew Cathrow <acath...@redhat.com> [2012-06-24 21:11]: > > > ----- Original Message ----- > > From: "Andy Grover" <agro...@redhat.com> > > To: "Shu Ming" <shum...@linux.vnet.ibm.com> > > Cc: libstoragemgmt-de...@lists.sourceforge.net, engine-devel@ovirt.org, > > "VDSM Project Development" > > <vdsm-de...@lists.fedorahosted.org> > > Sent: Sunday, June 24, 2012 10:05:45 PM > > Subject: Re: [vdsm] [Engine-devel] RFC: Writeup on VDSM-libstoragemgmt > > integration > > > > On 06/24/2012 07:28 AM, Shu Ming wrote: > > > On 2012-6-23 20:40, Itamar Heim wrote: > > >> On 06/23/2012 03:09 AM, Andy Grover wrote: > > >>> On 06/22/2012 04:46 PM, Itamar Heim wrote: > > >>>> On 06/23/2012 02:31 AM, Andy Grover wrote: > > >>>>> On 06/18/2012 01:15 PM, Saggi Mizrahi wrote: > > >>>>>> Also, there is no mention on credentials in any part of the > > >>>>>> process. > > >>>>>> How does VDSM or the host get access to actually modify the > > >>>>>> storage > > >>>>>> array? Who holds the creds for that and how? How does the user > > >>>>>> set > > >>>>>> this up? > > >>>>> > > >>>>> It seems to me more natural to have the oVirt-engine use > > >>>>> libstoragemgmt > > >>>>> directly to allocate and export a volume on the storage array, > > >>>>> and > > >>>>> then > > >>>>> pass this info to the vdsm on the node creating the vm. This > > >>>>> answers > > >>>>> Saggi's question about creds -- vdsm never needs array > > >>>>> modification > > >>>>> creds, it only gets handed the params needed to connect and use > > >>>>> the > > >>>>> new > > >>>>> block device (ip, iqn, chap, lun). > > >>>>> > > >>>>> Is this usage model made difficult or impossible by the current > > >>>>> software > > >>>>> architecture? > > >>>> > > >>>> what about live snapshots? > > >>> > > >>> I'm not a virt guy, so extreme handwaving: > > >>> > > >>> vm X uses luns 1& 2 > > >>> > > >>> engine -> vdsm "pause vm X" > > >> > > >> that's pausing the VM. live snapshot isn't supposed to do so. > > > > > > Tough we don't expect to do a pausing operation to the VM when live > > > snaphot is undergoing, the VM should be blocked on the access to > > > specific luns for a while. The blocking time should be very short > > > to > > > avoid the storage IO time out in the VM. > > > > OK my mistake, we don't pause the VM during live snapshot, we block > > on > > access to the luns while snapshotting. Does this keep live snapshots > > working and mean ovirt-engine can use libsm to config the storage > > array > > instead of vdsm? > > > > Because that was really my main question, should we be talking about > > engine-libstoragemgmt integration rather than vdsm-libstoragemgmt > > integration. > > for snapshotting wouldn't we want VDSM to handle the coordination of > the various atomic functions?
Absolutely. Requiring every management application (engine, etc) to integrate with libstoragemanagement is a win here. We want to simplify working with KVM, storage, etc not require every mgmt application to know deep details about how to create a live VM snapshot. > > > > Thanks -- Regards -- Andy > > _______________________________________________ > > vdsm-devel mailing list > > vdsm-de...@lists.fedorahosted.org > > https://fedorahosted.org/mailman/listinfo/vdsm-devel > > > _______________________________________________ > vdsm-devel mailing list > vdsm-de...@lists.fedorahosted.org > https://fedorahosted.org/mailman/listinfo/vdsm-devel -- Ryan Harper Software Engineer; Linux Technology Center IBM Corp., Austin, Tx ry...@us.ibm.com _______________________________________________ Engine-devel mailing list Engine-devel@ovirt.org http://lists.ovirt.org/mailman/listinfo/engine-devel