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VC Multi Enclosure Stack - Enclosure substitution

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VC Multi Enclosure Stack - Enclosure substitution

Pere was looking for enclosure replacement guidance:




We are in a project in which we need to fully replace an enclosure and all its associated VC modules. This enclosure is the base enclosure of 2 enclosures of a multi enclosure VC stack.


Our target is to keep as much as possible the profiles as they are, specially keeping the MAC and WWNs assignations exactly the same. The customer has followed a not very regular profile creation criteria, so the profiles present non consecutive MAC/WWN. Also, a HP-Predefined pool is used, both MAC and WWN.


Thinking on the procedure to deal with the situation:


-          In order to be able to take out the base enclosure, the only solution would be to delete de VC domain, taking a backup on the whole VC configuration.

-          Install the new hardware (enclosure+VC modules, moving servers…) and recreate the domain using the previously backup script.

-          We can try to recreate the profiles manually and trying to match the WWN/MAC assignations, but this may be a nightmare, since the assigns are not very consecutive and is a mistake-easy procedure.

-          Other way around trying to re-create the profiles forcing the WWN/MAC for each particular profile, but then should go to “User-Defined”?


The question: what would happen if we recreate the domain using the script and trying to keep the MAC/WWNs exactly the same? Would they go to “User-Defined” ? What would happen to the future MAC/WWN assignations? Would they be assigned automagically by VC or the customer will need to assign them manually (we want to avoid this).


Any ideas how to do it ?




Reply from Mark:




I will try to answer your question with some examples.

I am substituting an actual range such as HP Defined 1 and calling it ( Pool A with addresses 1-100) so I can make my point easier.


Current ME Domain – Using MAC/WWN Pool (Pool A 1-100)

If you were to delete and recreate the Domain from a Script, and select Pool A 1-100… to get the MAC/WWN to stay with a profile, you will have to use “User-Defined”

For instance….

MAC Pool = Pool A (1-100)

WWN Pool = Pool A (1-100)

Profile 1 may say User-Defined MAC=1 WWN=1

Profile 2 may say User Defined MAC=50 WWN=50

Profile 3 may say User Defined MAC=99 WWN=99


New profiles you create without the denotation of User-Defined will come from the Pool A 1-100, excluding 1 and 50 & 99. Because you have already set them with User-Defined, VC took them out of the pool as though they are Externally managed.

If you ever delete Profile 1 and Profile 2 & 3, those addresses (in this case 1 & 50 & 99) are NOT returned to the pool. That means they are gone forever in terms of VC using them when creating new profiles. You could still use them again, as long as you did it with User-Defined.


The problem you get into is let’s say the pool is (1-100), and you use User-Defined to assign MAC/WWN based on the old config, and 50 MAC/WWN are used.

If you delete those profiles at a later date, those 50 MAC/WWN are not returned to the Pool for automatic use by VC when creating new profiles. So now your pool just shrunk in half.


The other enclosure of the original ME setup Cannot use the same range or preserver MAC/WWN or you risk duplication.


So yes, this is possible to keep the old assignment of MAC/WWN to a profile and also create new profiles that automatically pull from the unused defined pool.




Also input from Pierre:




I had to face this situation in the past, all blade boot from SAN, and some blade in cluster, so keeping the same MAC and WWN was important. I took screen shot of each server profile to record Virtual Serial number, Virtual MAC, and Virtual WWN. I did use the VC simulation with the same HP predefine range and rebuild each profile in the simulator to find the order of profile creation, NIC assignation and Fabric assignation. I did start the process by following the Virtual serial number to give me the order of profile creation.


It took me about 2 hours (I had 16 servers only) to document all the steps in sequence to recreate the domain.  You can do this all off line on your PC. When you have define the steps in the right order, it is easy to rebuild the domain at the customer site.


My 2 cents.




Any other comments or suggestions?