[libvirt] Re: iSCSI Multi-IQN (Libvirt Support)

[Shyam_Iyer at Dell.com]

> >> Shyam_Iyer at Dell.com wrote:
> >>>> I like the functionality.  To restate what I said when you first
> >>>> proposed it, though, each pool is currently based on one iSCSI
> >>> session,
> >>>> so to preserve that paradigm, you should only allow zero or one
> >>>> initiator IQNs per pool.  If the pool contains an initiator IQN,
> it
> >>>> will
> >>>> be used when creating the session.  If it does not contain an
> >>> initiator
> >>>> IQN, the system default initiator IQN will be used.  If you
> require
> >>>> multiple initiator IQNs, you create multiple pools, one per
> >> initiator
> >>>> IQN each with the same target.  I think that approach will result
> > in
> >> a
> >>>> very small patch.  Do you have a specific use case for which that
> >>>> approach would not work?
> >>>>
> >>>> Dave
> >>>>
> >>> Yes.
> >>>
> >>> Let us say I  want to consider the LUNs behind a Target IQN as
pool
> >>> A.(Target centric terminology)
> >>>
> >>> If each initiator iqn creates separate pools than there will be
> >>> duplicity of the same set of LUNs. And this is a side effect not
> >>> necessarily a deliberate one.
> >> I'm not sure I understood you.  If a LUN is visible on multiple
> >> sessions, there's going to be duplication of LUNs regardless of
> > whether
> >> you use one pool with multiple sessions or multiple pools with one
> >> session per pool, because you're still establishing those sessions.
> >> You're also not guaranteed to have the same set of LUNs on both
> >> sessions, so you can't trust that the set of LUNs you get on one
> >> session
> >> is the same as the set on another session.
> >>
> >
> > Sorry. I wasn't clear.
> >
> > The present design allows the following -
> 
> Hi Shyam,
> 
> Your ASCII diagram got mangled by the emailing process.  Would you
mind
> sending a text document with it?  I think I see what you're saying,
but
> I'd like to confirm with your diagram before I comment further.
> 
> Dave

Dave- Attached diagram doc describes the use cases.

Thanks
-Shyam
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