On Solaris V8, for 32-bit DB2 UDB instance, each instance can have up to around 3.7 GB.

So, given that a system has 32 GB of RAM; we can have 6 multiple instances, each instance totaling up to 3.7 GB. Is this right?
Example:
Database 1 in instance 1 - 3 GB
Database 2 in instance 2 - 3 GB
Database 3 in instance 3 - 3 GB
Database 4 in instance 4 - 3 GB
Database 5 in instance 5 - 3 GB
Database 6 in instance 6 - 3 GB

Total of 6 Instances with one 32-bit database in each instance, all instances and databases running concurrently, using about 18 GB of RAM. Is this possible? Please clarify.

TIA.

Yes, that is basically correct, assuming that each instance can address up to 3.7 GB in Solaris.

Thanks for the reply.

On the other hand, is it that across all 6 instances we can have only 3.7 GB?

Thanks in advance.

I am not sure where you got the 3.7 GB number (I personally don't know the correct number for DB2 instances on Solaris). But whatever the correct number for DB2 on Solaris (2 GB, 3.7 GB, etc.), that is the amount of memory that can be addressed by each instance, not the total of all instances. So if you create enough instances, you can utilize all the memory on that machine. As I stated in my previous answer, you assumption in the original post is correct.