Re: Virtualized VMS in clusters (general questions)

In article <485FACBE.22618.84D8DB9@xxxxxxxxxxxxxxxxx>, "Stanley F. Quayle" <infovax@xxxxxxxxx> writes:
I think the relatively trivial answer is to run your virtual nodes as
satellite nodes over Ethernet, and then everything just works.

This does work in the current CHARON-* (VAX, Alpha) products.

Is there some way in which I can dedicate a real host Fibre Channel
connection to my virtual machines?

The new versions of the CHARON products will support FC device names. That will allow
you to interoperate on a SAN with other CHARON or physical systems running FC

Ooh. Okay, that seems to answer a bunch of my questions. (The emulated VMS
box sees the same device name / unit-number that the real host sees? If so,
good deal.)


What about single-system-disk clusters?

This works now, if both systems can access the same disk directly, just as with physical
systems. You could use a multi-port disk box, iSCSI, SAN, etc.

Who arbitrates access to it? Can you do shadowed system disk on it?

The Lock Manager. You could shadow the disk if you were running a multi-site CHARON
cluster, no problem.


But the Lock Manager can't prevent the non-VMS host on which the virtualized
VAX/Alpha is running from doing whatever it wants to the disk. (Of course, it
can't prevent a malfunctioning disk controller from doing a wild write on a
disk even in a fully-non-virtual environment; this would have the same effect.)


On the Itanium-emulated-on-Itanium approach (which isn't supported until
VMS 8.4) can you successfully run a multi-node cluster all on one physical
box with a single system disk?

Good question. Have to ask HP on that one...

But I'm not clear whether the hp/ux virtual switch supports, eg, DECnet,
MOP, SCS packets

There's really no point to it otherwise.

I'd think so, but (a) the hpvm project is on hp/ux and they'll have a bunch
more hp/ux and windows clients than VMS clients. If the switch is a proper
switch and just passes packets, great, it'll all work for everybody. If they
implemented per-protocol support - well, at one point Cisco charged extra to
support DECnet packets, so who knows. I'd expect all IP and trad Unix-related
services (bootp, tftp, etc) to be supported, but thought it was worth asking
whether the legacy-Digital protocols were supported, especially in light of
TCP/IP clustering coming in the same OS release on which virtualized VMS
is supported. What if you needed TCP/IP clustering because SCS traffic
wouldn't pass the virtual switch? [I'm just explaining what I was wondering
about, really not trying to start a rumor.]



Can you do host-based volume-shadowing on SAN disks that are actually being
presented by non-VMS hosts (if that's how that works at all)?

Presented by other clients connected to the SAN?

Didn't know another word for "presented" here. I meant, EVA presents to
non-VMS host, non-VMS host runs virtualized VAX/Alpha/Integrity (which sees
disk/file/whatever as a device name specified in local config or in startup
command for virtual machine); can HBVS work. I think the answer is "yes",
from what you say above and other people tell me.


How about on container files presented by the host?

That's in CHARON today, whether SAN-connected or local disk.

So I could have cluster-visible DS devices in which each "disk" was actually
a container file on Windows disk. It makes me nervous, but it's pretty cool.

Thanks!

-- Alan
.

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