Operating System - OpenVMS

Booting without joining a cluster?

 
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Jan van den Ende
Honored Contributor

Re: Booting without joining a cluster?

Phil,

please _DO_ give due attention to Hoff's and Jon's warnings.
OTOH, this exact path is what allows for, and is fully supported for, the so-called "rolling upgrade".
- (if common system disk:) get a current COPY of the system disk.
- boot one system off of that WITHOUT joining the cluster AND WITHOUT MOUNTING ANY OTHER DISKS!
- on this system do the upgrade.
- boot into the cluster off that upgraded disk (you now have a mixed-version cluster)
- if common disk, (re-)boot other system(s) off of the upgraded disk; if separate system disks, repeat for each SD.

So YES, the concept is well known, BUT, strict precautions are necessary, and the "standalone" system should be used for NOTHING else!

hth

Proost.

Have one on me.

jpe
Don't rust yours pelled jacker to fine doll missed aches.
Robert Gezelter
Honored Contributor

Re: Booting without joining a cluster?

Jan, Jon, Hoff, et al.,

I have had a sidebar conversation with Phil, and uncovered some details concerning his situation that did not quite come out in the posting that started this thread.

Apparently, the situation involves a hardware failure involving the second CPU, and a cluster that was reduced from three to two nodes without any changes in the voting parameters.

I talked him through the procedures for a conversational boot, and strongly cautioned concerning bringing the second system back, if it is repaired.

- Bob Gezelter, http://www.rlgsc.com
John Gillings
Honored Contributor

Re: Booting without joining a cluster?

>(I don't remember if that does exist for
>Vax at 6.2?

The same Standalone DCL available for Alpha (the $$$ prompt) is also present on VAX distribution CDs, but curiously not well documented. I'm fairly sure it goes back as far as V6.2.

Boot from root 1 on a CD drive or image backup of a distribution CD on another disk:

>>> B/R5:10000000 DKA400

Even if the V6.2 CD doesn't have $$$, there's no reason you can't boot a later version. Just avoid doing anything that isn't back compatible to V6.2 (for example initializing disks with recent features like small cluster sizes on large disks enabled)
A crucible of informative mistakes
Mrityunjoy Kundu
Frequent Advisor

Re: Booting without joining a cluster?

perform a conversational boot...
>>>boot/R5:0,1 DUA0:
you will get sysboot prompt
sysboot>set VAXCluster 0
sysboot>continue
Hoff
Honored Contributor

Re: Booting without joining a cluster?

There are some considerations around that previous reply here pointing to VAXCLUSTER parameter and the conversational bootstrap.

-- the cited approach appears incomplete for its intended purpose (you will also want to set NISCS_LOAD_PEA0 to 0, as various versions of OpenVMS can treat these parameters as a pair, and as you'll probably want to cancel the parameter write); failure to have at least NISCS_LOAD_PEA0 can leave you in an odd state.

-- the approach of disabling the cluster when shared interconnections around can be an exceedingly hazardous answer (for the reasons cited previously in this thread; I've corrupted disks during testing, and have seen crashes due to driver confusion),

-- and the VAX console boot command syntax shown seems odd and seems to be mixing Alpha SRM and VAX syntax; AFAIK, VAX expects "BOOT /R5:10000001 ddcu" for a VAX console conversational bootstrap.)

The OpenVMS FAQ has sequences which include references to various of the console and platform permutations, as well. This in addition to convenience features, such as skipping the parameter write operation.

But -- as Bob G. mentioned a couple of posts back -- this bootstrap issue has been resolved off-line.