Re: [Engine-devel] Floating Disks implementation in REST-API

On 04/17/2012 05:26 PM, Ori Liel wrote: >> >>>> Floating disks should be both in the root context, and also in the VM >>>> context for each VM the floating disk is attached to, right? So floating >>>> disks would appear 1+N_attach times in the API, once in the root >>>> context, and once for each VM they are attached to. >>>> >>> >>> IIUC a floating disk is not associated with the VM in any way, and should >>> not appear in that VM's collection of disks. There's a similar feature of >>> activate/deactivate disk (http://www.ovirt.org/wiki/Features/HotPlug). >>> A deactivated disk is still associated with the VM, and should appear in >>> the VM's collection of disks. Perhaps this is the source of confusion. >> >> No that isn't it. I think have a bit of terminology mismatch. According to: >> >> http://www.ovirt.org/wiki/Features/DetailedFloatingDisk >> >> i think your use of the word floating is correct. I got confused as i >> thought that any disk could be floating, whether it was attached to 0 >> VMs, 1 VM, or 2 or more VMs. >> >> So before we go further, let's get things straight: >> >> - disk without any VMs => floating. It appears in the root context. >> - disk attached to 1 VM => normal state. It appears in the VM context. > > I think this type of disk should be shown in both contexts. > > If a user is looking at http://{hostort}/disks, I think he intuitively > expects to see all disks (attached or unattached). A disk will contain > reference to the VMs which it is attached to, and thus: > > - No VM-ids --> floating disk. > - One VM-id --> regular disk. > - Multiple VM-ids --> shared disk. iirc, shared disk is a flag on the disk to allow it to be shared. doesn't mean it is shared yet, rather can be shared.

> >> - disk attached to 2 VMs => shared disk. It appears in both VM contexts. >> >> Is that correct? >> >> Also can someone explain on how floating and shared disks are actually >> implemented in the BE? I imagine it's one of two ways: >> >> => The BE keep a global list of disks, each disk with zero or more >> references to a VM. >> => The BE keeps a special "floating" state independent of the number >> of VMs that it is attached to. >> >> Thanks, >> Geert > _______________________________________________ > Engine-devel mailing list > Engine-devel(a)ovirt.org > http://lists.ovirt.org/mailman/listinfo/engine-devel