Well, actually the program name would be QZDFMDB2 and it would be in library QSYS if you have QSHELL installed at V5R2 or later (or V5R1 with the proper PTF). That's just the name that they chose to give to that program. However, that is different from the QShell utility function that is also named 'db2'. Note that your database on your AS/400 is a DB2 database - its name is 'DB2 UDB for OS/400' or something very close to that.
