Future for MC/SG

[Duncan Edmonstone]

I note with interest that the MC/SG implemntation for Linux doesn't provide 'cluster lock disk' functionality - it would appear you must use an arbitrator node.

Is this the new direction for MC/SG? Or is this just due to a limitation in Linux?

Also on the topic of MC/SG -Where can I get some info on System Multi-Node Packages - how to set up what to use them for etc...

Cheers

Duncan

[Sridhar Bhaskarla]

Duncan,

I have no idea why cluster lock disk is not supported on Linux. It seems to me that the MC/Service Guard has been generalized on Linux. Arbitrator nodes come into picture for MC/Service Guard Metro and continental MC/Service Guard clusters.

I don't know if you already looked at these documents.

http://docs.hp.com/hpux/onlinedocs/B3936-90053/B3936-90053.html

For multisite clusters...

http://docs.hp.com/hpux/onlinedocs/B7660-90008/B7660-90008.html

-Sri

[Duncan Edmonstone]

Yes, I've looked at the manuals...

Obviously system mult-node packages are used when you are using VxVM in your cluster, but can I use them myself?

Thx

Duncan

[melvyn burnard]

The answer is that Linux has no concept of the idea of a cluster lock disc. To solve that issue, Linux/SG uses the idea of a quoum server, which is another node OUTSIDE the cluster, as opposed to the arbitrator nodes in Campus/Metro cluster that MUST be part of the cluster.
There is a possibility thath the Quorum server functionality may be also available for HP-UX/SG, but that is still to be decided/implemented.

As far as the MultiNode package is conncerned, what are you actually looking for?

[Duncan Edmonstone]

Melvyn,

Thanks for that... as for what I am looking for, if I knew that I'd probably be a more complete person than I am ;o)

But seriously... I have nothing particular in mind, its just when new functionality is added to a product I use, I'm interested in what it can do... System Muli-Node packages appear to have been introduced specifically for CVM, and as far as I can see, the documentation doesn't give you any idea of how else they could be used (maybe because they can't!) Sorry if I'm not being specific enough to give me a meaningful reply

Regards

Duncan

[melvyn burnard · Accepted solution]

ah, that explains it. I just wanted to confirm what you were referring to.
The package you are talking about is needed to be setup on a cluster where you wish to use CVM. This package MUST run on each node participating in the cluster, and is used to monitor/confirm that the correct processes are there for the VxVM daemons to keep CVM running.

You may want to read through:

Managing MC/ServiceGuard at:
http://docs.hp.com/hpux/onlinedocs/B3936-90053/B3936-90053.html

The section heading:
Creating a Storage Infrastructure with CVM

will hopefully shed light on your question

[Sridhar Bhaskarla]

I am not quite confident that I understood your question well.

May be I am getting confused with your multi-node with multi-site cluster due to the word "arbitrator". If you are not interested in setting up multi-site cluster but are interested in multi-node cluster on hp-ux, it's simple. HP recommends to have a cluster lock for a three node cluster but is not mandatory but is dependent on the risk that you can afford to. Configuring a multi node cluster is done exactly the same way we configure a two node cluster except for the lock disk and lock volume group that are not mentioned in cluster config file.

If you are talking about setting the cluster on Linux, I mute.

-Sri