[Engine-devel] SharedRawDisk feature detail

[Miki Kenneth]

----- Original Message -----
> From: "Itamar Heim" <iheim at redhat.com>
> To: "Maor" <mlipchuk at redhat.com>
> Cc: engine-devel at ovirt.org, "Yaniv Dary" <ydary at redhat.com>, "Miki Kenneth" <mkenneth at redhat.com>
> Sent: Sunday, February 5, 2012 6:59:32 PM
> Subject: Re: [Engine-devel] SharedRawDisk feature detail
> 
> On 02/05/2012 02:14 PM, Maor wrote:
> ...
> 
> >> 3. "The synchronization/clustering of shared raw disk between VMs
> >> will
> >> be managed in the file system. "
> >>
> >> either i don't understand what this mean, or it could be read with
> >> a
> >> misleading meaning.
> > Maybe the following rephrase will be more accurate: "The
> > synchronization/clustering of shared raw disk between VMs should be
> > based on external independent application which will be
> > synchronized
> > with the guest application."
> "The synchronization/clustering of shared raw disk between VMs is the
> responsibility of the guests. Unaware guests will lead to corruption
> of
> the shared disk."
> 
> >>
> >> 4. VM Pools
> >> VM Pools are always based (at least today) on templates, and
> >> templates
> >> have no shared disks.
> >> I'd just block attaching a shared disk to a VM which is part of a
> >> pool
> >> (unless there is a very interesting use case meriting this)
> > If there is no reason to attach shared disk to a VM from pool,
> > maybe its
> > also not that relevant to attach shared disk to stateless VM.
> > Miki?
> 
> I think pools and stateless are different. I can envision a use case
> where stateless guests would use a shared disk (say, in read only for
> same data).
Not sure what you mean here. I do think that if you have a pool of Servers (rather than desktops),
It is a valid use case to be able have a shared raw disk attached to it. 
I agree that this can be handled later on - but I would like the design at list to handle it.
> 
> 
> >>
> >> 6. future work - Permissions should be added for disk entity
> >> so who can add a shared disk?
> > Data Center Administrator or System Administrator will be
> > initialized
> > with permissions for creating shared raw disk, or changing shared
> > disk
> > to be unshared.
> > Regarding attach/detach disks to/from VM, I was thinking that for
> > phase
> > one we will count on the user VM permissions. If user will have
> > permissions to create new disks on the VM, he will also have
> > permissions
> > to attach new shared raw disk to it.
> 
> this means they can attach shared disks from other VMs they have no
> permission on...
> as i said earlier - need to think about this one some more.
>