[Info-vax] Looking to remote cluster my two OVMS machines. Questions. Need help!!!

[Stephen Hoffman]

On 2012-10-10 17:16:24 +0000, Len Whitwer said:

> On Tuesday, October 9, 2012 6:03:56 PM UTC-7, Len Whitwer wrote:
>> I have two ES40 Alpha servers running OVMS 7.1 (75 miles apart) 
>> Machines are identical for disaster recovery. (Using tape now) Using 
>> Decnet phase IV. (Not DECnet over IP) I have COMCAST between the two 
>> sites with speeds over 15mb. Looking to keep costs down!! Questions!!! 
>> 1. Has anyone already done this?? 2. What networking equipment will 
>> support DECnet. (Routing or bridging) o Have heard Cisco and Procurve 
>> might work. 3. Open to any thoughts?? Len Whitwer o 425-488-0710
> 
> Hi Stephen:
> 
> Thanks for all the info and advice. Yes you are right in that I do want 
> to persist.

Read the links I've posted, particularly the low-end cluster link.

> o I can move to less power hungary machines. (DS15's or even DS10L')

V7.1?  No, you can't.  <http://h71000.www7.hp.com/openvms/hw_supportchart.html>

Technically, even the AlphaServer ES40 won't run on that V7.1 version; 
that box needs V7.1-2 (and patches).

>   o I am stuck with old application that now runs on VMS 7.1

Few things are ever truly stuck.  Have you tried a newer release?  If 
it's your source code, have you looked at the details of the 
application?

If it's a third-party and there's no hope of resolving this issue, then 
this down-revision software requirement (problem, mess, whatever) is 
going to derail you sooner or later, if not for the version requirement 
then for some other reason that'll crop up.  Time to replace this 
package.

>     and I believe DECnet is the only network protocal I can use. (Can't 
> upgrade to OVMS 8.4)

Have you tried the V8.4 upgrade, or are you assuming that?

> Does VMS 7.1 Phase V    support DECnet over IP????

If you have protocol-transparent bridging in operation for your 
cluster, then you can get DECnet bridging - DECnet Phase IV or Phase V 
- as part of the package.

But again, DECnet is completely irrelevent to clustering.  DECnet uses 
its own protocols, where clustering uses its own SCS or (with V8.4) SCS 
over IP protocols.

DECnet may or may not be relevant to your problematic application.  But 
again, it's not relevent to clustering; that DECnet requirement was 
officially dropped at OpenVMS V6.2, but clustering worked fine without 
DECnet before then.

> o Yes-- I do want to use HBVS. (Could use 2nd NIC and split load??)

A second NIC does squat to add bandwidth to a ~15 Mb link.  And a full 
disk copy of a disk volume of reasonably capacity will jam that link 
solid for a long time, or it'll take even longer if you throttle it.  
Divide the disk capacity by the bandwidth for an idea of how long, best 
case.

Purchase a second 15 Mb link (and BGP-capable switches), and you still 
have a slow link.

>     The server is not very busy at all however I do need    continuious 
> availability if main server goes down.

You don't have the budget for that particular aspiration quite yet; 
from what I can tell.   A two-node configuration is not capable of 
continuous operations; it's only capable of primary-secondary 
configuration.  If the primary fails, the secondary will lock up until 
there's been manual intervention.  See the low-end clustering article 
that I linked to in the previous reply.  You'll need a third node to 
survive the failure of any single node without manual intervention, or 
the loss of that data link.

>   o Do you or do you know someone I can talk to regarding bridging
>     equipment that might be able to suggest an affordable (ie: Cisco
>     Procurve or etc)solution for me??

You need a protocol-transparent bridge, in Cisco-speak.

<http://www.cisco.com/en/US/tech/tk331/tk660/technologies_tech_note09186a0080094471.shtml> 


I don't know what HP refers to that capability with their ProCurve products.

Get somebody in to get to the bottom of this and sort out the versions, 
requirements and options.


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