Re: [Engine-devel] [vdsm] RFC: Writeup on VDSM-libstoragemgmt integration

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.

> engine -> libstoragemgmt "snapshot luns 1, 2 to luns 3, 4" > engine -> vdsm "snapshot running state of X to Y" > engine -> vdsm "unpause vm X" if engine had any failure before this step, the VM will remain paused. i.e., we compromised the VM to take a live snapshot. > engine -> vdsm "change Y to use luns 3, 4" > > ? > > -- Andy _______________________________________________ Engine-devel mailing list Engine-devel(a)ovirt.org http://lists.ovirt.org/mailman/listinfo/engine-devel