how can i check if OnlineJFS 4.1 vxfs is installed

[TTr]

> This license seems to be just for 11.23 and I can't see it for 11.31

That may be true for that paper that you have. On that paper, at the top section, there are two numbers
A service agreement ID and
System handle or account reference
These numbers are tied up to a server. If it is the 11.31 server you mentioned above, you are entitled to the 11.31 media and licence for all the optional software for free. The service agreement for the 11.31 server must of course be valid (annual maintenance paid for).