Open Stack

On 04/08/2019 01:45 AM, Manuel Sopena Ballesteros wrote:
> Dear Openstack community,
> 
> I have 1 physical node with x4 nvidia nv100 running 1 fat vm. 
> Additionally I am adding a nvme drive into that host and I would like to 
> attach the nvme drive to the vm. Ideally I prefer to avoid data 
> migration and redeploy the software.
> 
> My problem is that I don’t have another host with gpus so I am guessing 
> that the vm can’t be migrated. Am I right assuming this?
> 
> So far I thought about 2 possibilities but I don’t know whether they 
> would work:
> 
> Option 1: crate a new flavor with the pci device pass-through and resize 
> existing vm (I hope the new vm with the new flavor will have the nvme 
> attached).
> 
> Option 2: convert ephemeral virtual disk into a bootable volume. Destroy 
> vm. Create new vm with the new volume as a boot device.
> 
> Which option would be preferred? Is there any other think I can do?

Put your application data in a different location than your application 
configuration and operating system. Save that application state in a 
separate Cinder volume. You can then attach and detach the application 
state to a (much smaller) root disk image that just contains the 
operating system and installed application binaries.

Once you've done the above, then you won't need to fret about 
"avoid(ing) migration and redeploy the software".

Put the effort in up front to do this application state separation and 
your life will be much, much easier.

Best,
-jay