Server runs Linux (Suse V12)

Data Server Client V11.1 was installed. There are no databases on this server.

db2ls produces the following output:
Install Path Level Fix Pack Special Install Number Install Date Installer UID
/opt/ibm/db2/V10.1 4 Thu Nov 6 13:57:33 2014 EST 0
/opt/ibm/db2/V11.1 0 Mon Feb 26 15:24:34 2018 EST 0

I read that db2iupdt needed to be executed in order to update the instance to V11.1

IBM documentation notes:

If the DB2 copy installed in the DB2DIR2 directory is at level lower than the DB2 copy installed in the DB2DIR1 directory, issue the following command:

DB2DIR2/instance/db2iupdt -D db2inst2

Using the following: /opt/ibm/db2/V10.1/instance/db2iupdt /opt/ibm/db2/V11.1/instance. The second half of the command produced an error. I receive an error no matter what I put in that position.

So, I have the following questions:
a) What value does "instance" represent? There is not a database installed on the server?
b) What is "db2inst2" and what should be put in this location?

Any insight would greatly be appreciated.