Shared File system- lib access issue

I have a C++ binary executable installed in a file system which is shared across multiple solaris boxes.

When I start this executable from one of the boxes,I am able to start only 4 parallel instances and from the 5th instance onwards I am getting the following error.

fatal: libdb2.so.1: open failed

I am able to start only 4 processes from a shell.If I exist from current shell and start another 4 from new shell,it is working fine.

Is this something due to shared FS?

Are these CIFS (SMB) file shares or NFS shares?

Sorry for my ignorance.How to find that?