LUN, Device Group and Mount Points are correlated

I have flown 30 hours to reach Senegal for a Sun Cluster for Oracle HA UAT. Customer is a teleco in Senegal.

The following is what I have implemented for them due to a constraint I encountered at the Storage level:

Oracle and App are now residing on the same node at the same time. Always.

Ideally, one would like to have Oracle active on 1 node; and App active on the 2nd node. That would be best in term of performance.

However, there is only 1 LUN being created by the storage engineer before the whole setup was shipped from China. No one here in Senegal knows how to reconfigure the LUN.

What's the implication of 1 LUN?

Now, if one is a Software person like the customer, it would be very hard to appreciate the issue. I need to explain in a more layman term.

Let's look at the table below:

A software person can only understand until column 3 ("Mount Point on Solaris OS"). Beyond that, it would be fairly difficult to grab the terms like Device Group, LUN, etc..

In order to understand, we need to read from right-to-left (yes, the ancient Chinese way of reading).

If there is 1 LUN, there can only be 1 Device Group. If we only have 1 Device Group, then all mount points have to be defined under this group.

As such, as all mount points have to be always together, it implies all applications (Oracle and App) have to be always together.

The ideal architecture will be the one shown below:

Oracle on 1 node; App on the other node

In order to have such a setup, we need to define at least 2 LUN at the Storage level.