On 11/05/2014 10:26 PM, Mike Tutkowski wrote: > When you say the disk would be snapshotted, do you mean from the point of > view of the SAN or from the point of view of the hypervisor? >
Hypervisor. QCOW2 files support snapshots, so does RBD. When using iSCSI we usually create a VG on top of the LUN and then we can snapshot each LV which is mapped to a Instance. > A SAN snapshot is no problem. I'm mainly curious to see how this would work > for a hypervisor snapshot. > > Thanks! > > On Wed, Nov 5, 2014 at 2:24 PM, Wido den Hollander <w...@widodh.nl> wrote: > >> >> >> On 11/05/2014 10:18 PM, Mike Tutkowski wrote: >>> Hey Wido, >>> >>> Perhaps you know the answer to this: >>> >>> My main interactions with KVM have been in the form of data disks. >>> >>> I create a LUN on my SAN that gets passed to a VM as a data disk. >>> >>> In this situation, how would a snapshot of such a disk work? >>> >> >> The disk would be snapshotted, but at the same time the memory contents >> of the VM would be written to a new disk/file. >> >>> On XenServer and ESX, your data disk can be just a subset of the overall >>> LUN and hypervisor snapshots create new virtual disks that are stored >> right >>> next to the original ones on the same LUN. >>> >>> I'm un-clear how this works in KVM. >>> >> >> It would work about the same with KVM. >> >> You can look into the "virsh save" command of libvirt to see what it does. >> >> Wido >> >>> Thanks! >>> Mike >>> >>> On Wed, Nov 5, 2014 at 2:01 PM, Wido den Hollander <w...@widodh.nl> >> wrote: >>> >>>> >>>> >>>> On 11/05/2014 07:37 PM, Logan Barfield wrote: >>>>> This is a feature we would like to see as well. >>>>> >>>>> Does KVM have native support for VM/Memory snapshotting? If so what >> are >>>>> the barriers to getting this implemented? >>>>> >>>> >>>> KVM has the support, but there is a problem with the storage. >>>> >>>> Snapshotting a disk is simple, that's supported by QCOW2, LVM, RBD, etc. >>>> >>>> But when you want to snapshot a VirtualMachine you have to store the >>>> memory contents somewhere. >>>> >>>> That is something that hasn't been worked out. Do you create a >>>> additional 'disk' for storing the memory contents? >>>> >>>> That's the barriers I currently know for implementing it. >>>> >>>> Wido >>>> >>>>> >>>>> Thank You, >>>>> >>>>> Logan Barfield >>>>> Tranquil Hosting >>>>> >>>>> On Wed, Nov 5, 2014 at 1:20 PM, Andrija Panic <andrija.pa...@gmail.com >>> >>>>> wrote: >>>>> >>>>>> Anybody ? >>>>>> >>>>>> On 3 November 2014 15:23, Andrija Panic <andrija.pa...@gmail.com> >>>> wrote: >>>>>> >>>>>>> Hi guys, >>>>>>> >>>>>>> do we have any plans in some near future to imlement full VM KVM >>>>>>> snapshots. So not single volume snaphost, but a reall VM snapshots. >> It >>>> is >>>>>>> already there for Xen/VMware, but not KVM. >>>>>>> >>>>>>> Any thoughts, ETA, or difficulties to implement this ? >>>>>>> Any feedback greatly appriciated... >>>>>>> >>>>>>> Best, >>>>>>> >>>>>>> >>>>>>> Andrija Panić >>>>>>> >>>>>> >>>>>> >>>>>> >>>>>> -- >>>>>> >>>>>> Andrija Panić >>>>>> -------------------------------------- >>>>>> http://admintweets.com >>>>>> -------------------------------------- >>>>>> >>>>> >>>> >>> >>> >>> >> > > >
