Cluster Install Question

[node_runner]

Hi everyone. I'm about to set up our ZCS 5 installation on a RHEL5.1 Cluster between 2 nodes. The active/standby setup will be using Red Hat Cluster Suite 5.1 and use a Dell MD3000 shared storage array.

The Zimbra documentation for setting up a RedHat cluster mentions installing the LDAP and MTA components on separate servers than the Mailstore nodes. I just want a sanity check to make sure it isn't a problem to install the LDAP+MTA components on my two clustered nodes along with the mailstore and everything else? Since only 1 will be active at a time, I don't see how this would be a problem but I thought I'd make sure first.

Also, we are going to be using a fencing mechanism (Dell PERC controllers) that is supported by the latest RHCS but isn't an option in the Zimbra installer script for setting up cluster nodes. Should I just select an APC fencing config during the install and then use the RHCS management tools to later go back in and change the fencing config?

[brian]

You are probably looking for this: RHEL5 support for RHCS
Bug 18197 - RHEL5 support for cluster/RHCS

[node_runner]

Brian, thanks for the reply. I understand that RHCS 5 is supported. I just wanted to make sure that the example used in the Zimbra documentation on how to set this up isn't the only supported "method" or "architecture design".

The example in the guide shows two zimbra mailstores being clustered together using RHCS 5. But they show the MTA and LDAP components being installed on separate, non-clustered machines. I just wanted to make sure that it was just the way the decided to design things in the example and that I don't necessarily have to install the MTA and LDAP components on separate, non-clustered machines.

[brian]

I think you misunderstood the bug, RHEL5 clustering is currently not supported.

As far as your design approach there are currently 2 install guides. Single (1+1) and a multinode (m+n) install guides. You'll want to get the 1+1 install guide. A single system or 1+1 cluster will have all services managed. The multinode will have separate boxes for LDAP/MTA with the mail store boxes clustered.

The automated cluster.conf generator that we provide only supports the 2 fencing devices listed and is provided as really as a starting point. You can use the generated one as a starting point and then use the RedHat tools to modify the cluster.conf and define your own fencing device or otherwise tweak the configuration.

[Klug]

Modifying the cluster.conf to handle DRAC is extremely easy.

IMHO, you should force action to "off" (instead of the default), in order to have an operator check the fenced node and understand why it was fenced.

[node_runner]

Brian,

Thanks for the input. That is what I suspected. I really appreciate your help, but I'm getting conflicting info as to whether or not RHCS 5 is supported. The "ZCS Clustiner Installation" guide says "Red Hat Enterprise Linux Cluster Suite version 4, Update 5 or later" is supported. My rep from Red Hat also told me that they fully support Zimbra with RHCS 5 and even offer up to level 3 tech support for issues with Zimbra. I also put in a support request with our ZCS support contract asking the same question, but I don't have a response yet.

I mean no disrespect, but I surely hope you are wrong about RHCS 5 support. I've spend the last week being talked into buying the RHCS component and I'll be in hot water at my company if I've wasted a week of time and thousands of dollars.

[brian]

I can give a pretty definitive answer that it's not supported until bug 18197 is resolved.

[Klug]

Originally Posted by node_runner

"Red Hat Enterprise Linux Cluster Suite version 4, Update 5 or later"

That's RCHS 4.5 or 4.6 (no higher version yet).

Originally Posted by node_runner

My rep from Red Hat also told me that they fully support Zimbra with RHCS 5 and even offer up to level 3 tech support for issues with Zimbra. I also put in a support request with our ZCS support contract asking the same question, but I don't have a response yet.

I'm afraid you'll have to tell your RH rep he's wrong.

I've hit a similar issue in january when setting up a cluster for a customer.
They (the customer) were told by RH they could use RH5 and RHCS5 so bought it...
But it's not supported, so no ZCS setup on this.

So we went through a big pain
RHAS 5 includes RHCS 5 and the right to use RHAS 4. But RHAS 4 does not include RHCS 4.
So we had to order RHCS 4 (took several days) and use it with the RHAS 5 licence (that allows your to use RHAS 4).

Originally Posted by node_runner

I mean no disrespect, but I surely hope you are wrong about RHCS 5 support. I've spend the last week being talked into buying the RHCS component and I'll be in hot water at my company if I've wasted a week of time and thousands of dollars.

Just "just" need to get RHCS 4, you can keep your current RHAS 5 license.