[ovirt-users] [RFI] oVirt 3.6 Planning

[Nir Soffer]

----- Original Message -----
> From: "Nicolas Ecarnot" <nicolas at ecarnot.net>
> To: "Nir Soffer" <nsoffer at redhat.com>
> Cc: users at ovirt.org, "Federico Simoncelli" <fsimonce at redhat.com>
> Sent: Saturday, September 13, 2014 9:24:55 PM
> Subject: Re: [ovirt-users] [RFI] oVirt 3.6 Planning
> 
> Le 13/09/2014 17:34, Nir Soffer a écrit :
> >> For God's sake, please, prevent "secondary" storage domains (anything
> >> other than the master, especially iso and export) to completely block
> >> the whole thing when being unavailable.
> >> To many users suffered from this in the last two years I participate at
> >> this mailing list (including me).
> >
> > I think this is true for ISO and export domains for some time.
> 
> In 3.4 at least, this is still true and is a problem.
> At least, if we can get rid of this and just mark these iso and export
> domains as unusable, and still do every other non-related operations,
> this would be very useful.
> 
> > It will not work for data domains - if you have vms with disks on what you
> > call "secondary" data domain, how would you migrate these vms to a host
> > that
> > cannot see the "secondary" domain?
> >
> > In 3.6, there will be no "master" domain, so any data domain will be
> > important
> > as any other data domain.
> >
> > Maybe what do you like is to have more control on which domains are
> > critical,
> > and which are not. A domain which you mark as "non-critical", or
> > "secondary",
> > will not cause the host to become non-operational when the host cannot see
> > this domain.
> >
> > So you would not be able to migrate some vms to a host that cannot see the
> > secondary domain, but since *you* marked it as "secondary", it is not a
> > problem
> > for you.
> >
> > What do you think?
> 
> This proposition is perfect.
> I don't know whether being able to mark some storage domain as more
> precious than other will be useful, when their absence won't be a
> blocker anymore?

The idea is to let you define which storage domains are "required" and 
which are not, lets call them "optional".

If a required storage domain cannot be seen, a host be become
non-operational.

If an optional storage domain cannot be seen, you will get a warning
but the host will function normally.

If you try to migrate a vm to a host which cannot see the storage
domain used by that vm, the operation will fail.

When a "required" storage domain is down, you would be able to
change it to "optional", and continue to work with the other 
domains in degraded mode. Some vms will not able to run, but
other vms that do not depend on problem domain will not be
affected.

I hope that I understood your question correctly.

Nir