[Engine-devel] VM hibernation to storage domain

[Itamar Heim]

On 12/12/2011 10:31 PM, Jon Choate wrote:
> On 12/12/2011 02:10 PM, Yaniv Kaul wrote:
>> 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 at 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.
> Those all seem to have the possibility of getting the wrong disk. If the
> cost of getting the wrong disk is low anyway then I would argue that we
> don't need to find the system disk and we could hibernate alongside any
> disk.

1. how about KISS and choose the disk the user flagged as type = system 
(the field already exists and is used today. iirc, backend doesn't even 
allow choosing more than one, etc.)
2. diskless VMs - fail the operation. it would fail if you try to 
hibernate from inside the guest as well (S4) which are considering 
moving to.