topic Re: Restore 16 Gb reserve memory on system with 8 Gb total in Operating System - OpenVMS

Restore 16 Gb reserve memory on system with 8 Gb total

Clark Powell — Fri, 07 May 2010 13:12:32 GMT

I'm doing a disaster recovery exercise and need to restore a system that is set up with 16 Gb of reserve memory onto hardware with only 8 Gb total of memory. Will the reserve memory be automatically turned off at boot due to the size conflict or will the system not boot? If it won't boot then how might I lower the reserve memory request before boot? It is Alpha OpenVMS 8.3.

Re: Restore 16 Gb reserve memory on system with 8 Gb total

Hein van den Heuvel — Fri, 07 May 2010 13:20:26 GMT

Hmmm, and the systems are otherwise identical?
Same network interfaces, same drive names and stuff like that?
I should think that a tailored systems disk will be unavoidable.

Surely the Reserved memory is for example for a large Oracle SGA, and the Oracle Init/SP file needs to be tweaked also to avoid thinking it has more than 8GB to play with!

Anyway, Get a Personal-Alpha or Free-Axp, and just try ?! Good fun!

http://www.migrationspecialties.com/FreeAXP.html

http://www.stromasys.ch/personalalpha/

Hein

Re: Restore 16 Gb reserve memory on system with 8 Gb total

Bill Hall — Fri, 07 May 2010 14:01:57 GMT

Clark,

Worst case would be a conversational boot to set startup_p1 to "MIN" and bring the system up. Then run sysman to reconfigure reserved memory.

Or, you could rename the reserved memory data file, sys$system:vms$reserved_memory.data while booted from the vms binary CD.

Bill

Re: Restore 16 Gb reserve memory on system with 8 Gb total

Robert Gezelter — Fri, 07 May 2010 14:31:03 GMT

Clark,

Are you already in the midst of the exercise? If so, then I concur with Hoff. If the exercise is still being planned, a longer range approach may be in order.

This is one of those cases why I create SYS$NODE_SPECIFIC directories, and then create alternate boot roots (I mentioned this in my 2009 HP Enterprise Technology Forum presentation; available at: http://www.rlgsc.com/hptechnologyforum/2009/continuous-openvms.html ). It helps separate hardware dependencies (that live in the SYS$SPECIFIC) from cluster node definitions (that live in the SYS$NODE_SPECIFIC tree).

Where I do this, I use the indirection feature of AUTOGEN to pull in the node-specific parameters from the common source pointed to by SYS$NODE_SPECIFIC (e.g., a directory tree on the system disk with a root of [CLUSTER_NODES]).

It makes it easier to maintain alternate boot scenarios for different boot members.

- Bob Gezelter, http://www.rlgsc.com

Re: Restore 16 Gb reserve memory on system with 8 Gb total

Hoff — Fri, 07 May 2010 15:28:16 GMT

Might cheap to toss eight (more) gibibytes into the box?

One less difference.

Four (new) sticks of DDR3 two-GiB (2 gibibytes) DDR3 1600 memory looks to be around US$400 from Corsair. That'll likely be a different and probably higher price for official HP memory for this (unspecified) server. But then I've occasionally purchased whole servers just for spare parts and extra memory; there are deals to be had.

Re: Restore 16 Gb reserve memory on system with 8 Gb total

P Muralidhar Kini — Fri, 07 May 2010 17:32:50 GMT

Hi Clark,

>> Will the reserve memory be automatically turned off at boot due to the size conflict
>> or will the system not boot?
To avoid any problems, you may choose to modify the reserved memory configuration
as per the new system before you do the first full mode on the new system.

>> If it won't boot then how might I lower the reserve memory request before boot?
Reserved memory gets setup when the system boots up in the full mode
(i.e. normal mode). But when the system boots in MINIMUM mode, the reserved
memory does not get setup.

You can boot the 8GB system in MINIMUM mode first, so that reserved memory does
not get setup and then configure the reserved memory as per the 8GB system.
Once this is done, you can boot the system in NORMAL mode.

For Booting system in different modes -
http://h30266.www3.hp.com/odl/vax/opsys/vmsos73/vmsos73/6629/6629pro_011.html
Section -> A.1.4 Booting with Minimum Startup

For configuring the reserved memory -
http://h71000.www7.hp.com/doc/73final/5841/5841pro_049.html

Hope this helps.

Regards,
Murali