Re: [Engine-devel] VM hibernation to storage domain

On 12/12/2011 21:04, Jon Choate wrote: > On 12/12/2011 01:46 PM, Yaniv Kaul wrote: >> On 12/12/2011 19:22, Jon Choate wrote: >>> Is there any reason anyone can think of why we would need to >>> specify a specific storage domain for a VM to use when it >>> hibernates? Ideally we could just grab any storage domain that has >>> space and use it for hibernation (as long a we remember where we >>> did it!). >>> >>> thoughts? >>> _______________________________________________ >>> Engine-devel mailing list >>> Engine-devel(a)ovirt.org >>> http://lists.ovirt.org/mailman/listinfo/engine-devel >> >> Probably for the same reason we enforce all VMs disks to be on the >> same storage domain. Habit. > Eliminating this dependency would be part of the feature to allow VMs > to have their disks on multiple storage domains. >> But I also think it make sense, for the hibernation file to be in >> the same SD as the system disk. There's also a higher chance that >> domain will be online and available to the host. >> Y. > Is it possible for ovirt-engine to identify which disk is the system > disk? In several ways: 1. Guess. 2. The first 3. Use the one with the 'Is Bootable' flag.

Y. > > What should the algorithm be for determining a storage domain to > hibernate a diskless VM? None, we should only support S4 and say farewell to the external hibernation. I don't think there is a good enough reason to keep it (Ayal might disagree, but I disagree with his reasons). > > It seems like things would be simplified if we did not restrict > ourselves and could use any available storage domain regardless of > whether the vm has disks or not. Perhaps. What's the real benefit, except of freedom of choice? I personally would look at compressing that hibernation file, btw. Always annoyed me the size of it, and I expect fast compression to enable faster suspend-resume cycles. I believe libvirt support some compression methods. Y.