Can rx8640 join into a 3-node blade (BL870) cluster

[Ravi-Joshi]

Hello All,

We have a 3-node SG 11.19 cluster. All the 3 nodes are on BL870 (Blade hardware) running HP-UX 11.31.

We want to add 4th node which is on rx8640 running HP-UX 11.31 and SG 11.19.

From the software-wise, all are same. But from hardware-wise, the 4th node is rx8640. Does this make any

difference. I am wondering whether it is doable as 4th node is on different hardware. The other differene is

rx8640 uses apa. We have lan900 as public IP and lan901 as failover IP. On the 3-node existing cluster which are

on blade, there is no apa. They just use nic i.e. lan4 is public and lan5 is failover.

Thank you

RJ

[Matti_Kurkela]

As long as all the nodes are of the same hardware architecture (in your case, IA64) and capable of running the same versions of the OS and Serviceguard, it is OK. Mixing hardware architectures is possible but usually makes it harder to configure the applications. Mixing OS or Serviceguard versions is allowed only temporarily during rolling upgrades of the cluster.

As all your servers are using the IA64 architecture (i.e. Itanium CPUs) and have the same HP-UX version and Serviceguard version, the different hardware model is not an issue. The presence/absence of APA should not be an issue either.

[Ravi-Joshi]

Thank you MK.

The existing 3-node cluster that are on Blade servers use Xeon (Intel) CPU. The 4th node which is

going to be in this cluster (rx8640) uses IA processors. Do you think it makes any difference.

We updated the cluster config file and ran cmcheckconf successfully.  We did this just to check.

We are going to run cmapplyconf during the cutover weekend. As per your thought, do you think it is doable.

We thought since cmcheckconf ran succussfully, cmapplyconf would also do so. But we don't know until we

try it during the cutover weekend.

RJ

[Matti_Kurkela · Accepted solution]

All existing BL8xx blade models have Itanium (IA64) CPUs, not Xeons, as far as I know. (They are also branded as Integrity blades, as opposed to ProLiant blades.)

The Xeon blades have so far had smaller model numbers, like BL6xx and below.

On the other hand, it would be entirely possible to have a Serviceguard cluster running on Xeon CPUs - but that cluster would be running some version of Linux, with HP's "Serviceguard for Linux" cluster software. Although HP-UX and Linux versions of Serviceguard can share a quorum server and can be managed with the same Java-based tools, they are still two different cluster products and cannot form a single cluster together.

If the model numbers you mentioned in the thread title are accurate, your configuration should be OK. The fact that cmcheckconf confirms this. So I'm afraid I must suggest you to double-check the CPU model specifications of your blades...

[Ravi-Joshi]

Thank you MK.

It was my fault that the blades that we use have xeon. They have IA processors. HP-UX does not run on

xeon, runs only on IA I think.

So I am good.  The existing 3-node blades are IA and 4th would be node is also IA.

Thank you for your help.

RJ