[Engine-devel] [vdsm] RFC: New Storage API

[Adam Litke]

On Mon, Dec 10, 2012 at 02:03:09PM -0500, Saggi Mizrahi wrote:
> 
> 
> ----- Original Message -----
> > From: "Adam Litke" <agl at us.ibm.com>
> > To: "Saggi Mizrahi" <smizrahi at redhat.com>
> > Cc: "Deepak C Shetty" <deepakcs at linux.vnet.ibm.com>, "engine-devel" <engine-devel at ovirt.org>, "VDSM Project
> > Development" <vdsm-devel at lists.fedorahosted.org>
> > Sent: Monday, December 10, 2012 1:49:31 PM
> > Subject: Re: [vdsm] RFC: New Storage API
> > 
> > On Fri, Dec 07, 2012 at 02:53:41PM -0500, Saggi Mizrahi wrote:
> > 
> > <snip>
> > 
> > > > 1) Can you provide more info on why there is a exception for 'lvm
> > > > based
> > > > block domain'. Its not coming out clearly.
> > > File based domains are responsible for syncing up object
> > > manipulation (creation\deletion)
> > > The backend is responsible for making sure it all works either by
> > > having a single writer (NFS) or having it's own locking mechanism
> > > (gluster).
> > > In our LVM based domains VDSM is responsible for basic object
> > > manipulation.
> > > The current design uses an approach where there is a single host
> > > responsible for object creation\deleteion it is the
> > > SRM\SDM\SPM\S?M.
> > > If we ever find a way to make it fully clustered without a big hit
> > > in performance the S?M requirement will be removed form that type
> > > of domain.
> > 
> > I would like to see us maintain a LOCALFS domain as well.  For this,
> > we would
> > also need SRM, correct?
> No, why?

Sorry, nevermind.  I was thinking of a scenario with multiple clients talking to
a single vdsm and making sure they don't stomp on one another.  This is
probably not something we are going to care about though.

-- 
Adam Litke <agl at us.ibm.com>
IBM Linux Technology Center