[libvirt] [PATCH 6/6] storage:dir: adapts .refreshVol .refreshPool for ploop volumes

[Ján Tomko]

On Thu, Feb 18, 2016 at 05:04:16PM +0300, Maxim Nestratov wrote:
> 18.02.2016 16:46, Ján Tomko пишет:
> > On Wed, Feb 17, 2016 at 02:40:05PM +0300, Olga Krishtal wrote:
> >> To update information about ploop volumes inside the a single pool we need
> >> to be sure that it is the ploop directory and not some other directory.
> >> Ploop volume directory obligatory contains root.hds - image file and disk
> >> descriptor - DiskDescriptor.xml. If path to a volume is a path to some
> >> directory, we check the existance of this files.
> >>
> > With each ploop volume being a directory with a ploop disk image and the
> > XML, I think they deserve a separate pool type.

On second thought, the pool is still just a directory, it's the volumes
that are different, so it does belong in the directory-based pools.

That leaves the mixing of the ploop volumes with the ploop disk images,
don't we need a new STORAGE_VOL type?

> > The ploop image (root.hds) could be detected as such by the fs pool,
> > but creating and deleting the directories feels out of place in this
> > backend.
> 
> Actually one of the main intention of implementing ploop disk support in 
> storage pool was
> ability to make it possible to work with existing storage pools like 
> NFS, DIR, FS.

The 'image in a directory' still won't work with older libvirtd.

> Creating a
> separate  storage pool makes it impossible. Also, our future plans to 
> expand storage pools
> with new pool type like VZ storage and CEPH FS becomes worthless either.
> 

Jan