How to config VMScluster with 6 ES40s thru FC

[Song_Charles]

Hi,

My customer's applications will be migrated,
there are 6 ES40s and 1 MA8000 with 1TB disk room, they want put all the storage and servers into one VMS Cluster togather.

for VMS cluster could be support up to 96 nodes, I think it is no problem of this configuration.

My questions:
1.the customer's Environment was 2 Nodes VMScluster with V7.3-1 now, could I still use this version to configurte 6 Nodes VMScluster?

2.All ES40s were the same degree, how would I setup the VMScluster's parameters,
such as NODE_VOTE, EXPECTED_VOTE, QDSKVOTES...

3.I would assign the DISK_QUORUM to the common system boot disk (DGA0) and the disk must be the ODS-5 file system, could the disk be used as QUORUM DISK?

4.The customer's applications were run under ORACLE7/OPS, how about the performance of this VMScluster configuration?

B+R
Charles

[Robert Brooks_1 · Accepted solution]

I'm sure you will receive more detailed responses than mine . . .

A six-node cluster is not that big; you will have no trouble having six nodes connected into a fibre channel SAN. However, you should strongly consider upgrading to a supported version of OpenVMS Alpha; V7.3-1 is no longer supported and is not eligible for prior-version support.

Unless there is something a bit different about your proposed configuration, there is little-to-no reason to have a quorum disk for a six-node cluster.


-- Rob (VMS Engineering)

[Uwe Zessin]

1.) The maximum limit of 96 nodes has been established a loong time ago, but I would see if I could bring the operating system to a current, supported level.

2. Using 6 nodes, I would not use a quorum disk, give every node VOTES=1 and EXPECTED_VOTES=6

3. I would not use a quorum disk unless absolutely needed. Usually it is only used in two-node clusters. If you insist, I would choose a HSG unit with little I/O load.

[Robert Gezelter]

Charles,

One possibility that I would consider with the goal of minimizing downtime is bringing the new ES40 and the MA8000 into the current cluster, and then rolling the applications over to the new hardware. Using the dis-similar device support inherant in the latest releases of shadowing, it is even possible to move shadowsets from the old storage to the new MA8000 without even interrupting any production applications (see my presentation from HP World 2005, slides at http://www.rlgsc.com/hptechnologyforum/2005/1146.html).

Done carefully, the process of bringing the new hardware into the existing cluster, migrating the data and applications (in either order: applications first, or data first), and then removing the old equipment from the cluster, can be done with a minimum of downtime and disruption of access to users.

I hope that the above is helpful.

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

[comarow]

There are of course pros and cons of having a quorum disk. The biggest advantage is of course to boot any single node, or shutdown to any single node. Some people in Sans do not like a quorum disk, because if one node can communicate with the quorum disk, but their is a short gap in network connectivity, IT will become the cluster, and ALL the rest of the nodes will clue exit.

That being said, it is a rare occurance, but can happen.

Should you wish to have a quorum disk, it is not advisable to use the system disk. It is writing and reading from the quorum disk
a qdskinterval, and that is a load on the disk. Should it not get a response in time
(the system disk is busy) you will get lost connection to quorum disk.

The quorum disk should be a very lightly used disk, not a system disk.


Best of luck.
Bob

[Jan van den Ende]

Charles,

I would be a big favourer of Bob's plan, just use the existing cluster and extend it.
We did so several times already, with NO downtime.

The one thing you REALLY should do in that case, is upgrade to 7.3-2 (and latest patches) FIRST!!
(and that can also be done by rolling upgrade!).

If you have any specific questions on the upgrades, please ask.

Success!

Proost.

Have one on me.

jpe

[Phillip Thayer]

Charles,

If it were me doing this type of upgrade I would go with what Bob suggested. I have also done this type of migration and it worked very well. The first thing is to upgrade to a newer version of the OS that can be installed on the same shared system disk that you currently have. Then add in each of the ES40's one at a time until all 6 are added to the cluster. Use the SYS$STARTUP:CLUSTER_CONFIG command procedure to add nodes to the cluster because it will adjust the SYSGEN parameters as needed and ensure you don't cobble things up. Once you add a node let the system stabilize for a day or so and then add the next node. I like to do this so that I can trace problems easier. Main thing is do one change at a time so if something doesn't work properly you know what caused it. If you do more than one change at a time then you don't know which change caused the problem or if both changes combined caused the problem. Patience is a good thing when doing these types of upgrades.

Phil

[Robert Gezelter]

Charles, et al,

There is a typographical error in my post. The correct URL for my presentation is:

http://www.rlgsc.com/hptechnologyforum/2005/1146.html

The ITRC web site incorrectly generated the URL to include the punctuation at the end of the sentence.

My apologies, normally I try to catch those before hitting POST.

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

[BR764713]

Please IGNORE for the moment, the technology involved, SYSGEN parameters, quorum, voting, all that.

Look at the DESIGN of your application, what do you need from it?

Make sure you have all the components and infrastructure that will support your requirements in all the expected, and where possible the unexpected situations, and some mitigation of the worse of all possible scenarios.

Then and ONLY THEN, do you worry about the technical setup, and this should apply regardless of if you are using VMS, Trucluster, even Microsoft Cluster, VERITAS, it really is not important. You are confusing poking a few parameters into places where you need to take several steps back.

My advice here is start with your application needs, decide how that can be best provided. You have experience and possibly a little knowledge of a superlative operating system in OpenVMS, but even that can be incorrectly configured, and not provide the service you need without a good design. Consider bringing in a consultant with VMS knowledge and experience to assist you.

The OpenVMS website has some very recently published whitepapers which may be useful, www.hp.com/go/openvms

Nic Clews.

[Ian Miller.]

You are about to embark on a non-trivial upgrade project which will require careful planning if the project is to be a success with a minium of distruption. There are many variables to be considered and it sounds like you will need assistance beyond the informal help available in forums like this one. You should get in an exteral consultant who has performed this sort of upgrade before.

You certainly should take the oppourtunity to move to a supported version of VMS.