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HP OpenVMS Systemsask the wizard |
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The Question is: I have two vax 4000 705a in a cluster. I would like to use two others I have for hardware failover this is a dssi cluster and I connected all four systems together and set the bootflags so the replacement systems boot properly. when booting the old system works fine and the new system boots half way and hangs when I try to boot it. I know I can only boot one of them at a time because the boot from the same system segment. HELP The Answer is : You cannot have the same host name and the same SCSSYTEMID host address active in the same cluster at the same time -- and these values are paired, so the entire cluster must be rebooted if either the SCS node name or the SCS system ID (but not both) changes. Bootstrapping this configuration should involve great care as well, as cluster configurations with invalid VOTES and/or invalid (or creative) EXPECTED_VOTES settings can trigger user data corruptions. (For details on correctly setting the VOTES and EXPECTED_VOTES parameters, please see the OpenVMS FAQ.) If you endeavour to have two nodes booting from one root, this should work -- assuming that the hardware configurations of the pairs are sufficiently similar of course, and assuming that one of the two nodes in the pair is always and reliably down. That written, the OpenVMS Wizard would tend to use a cluster alias and would tend to keep all four nodes active, each with a unique host name and SCS host address. This tends to reduce the exposure to operator error, of course, and this allows all four hosts to be continuously tested through normal operation. You can turn on procedure verification and determine where the hang occurs, of course -- assuming the system has gotten that far. (With no details on when the hang occurs, no specific answer is possible.) The OpenVMS Wizard would also look to the exposure involved in the operator input -- human error is a common source of problems -- and the exposure to hardware-level failures in the storage area. DSSI is an old (and slow) storage technology, and the hardware involved in most DSSI configurations is aging and becoming coorespondingly more prone to hardware failures.
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