The Cisco MDS 9000 NX-OS Software Release 4.2 has been retired and is no longer supported.
End-of-Sale Date: 2012-07-31
End-of-Support Date: 2017-07-31
Cisco's End-of-Life Policy
You can view a listing of available Cisco MDS 9000 NX-OS and SAN-OS Software offerings that best meet your specific needs
If you want support information for the Cisco MDS 9000 NX-OS Software Release 4.2 documentation, it may be available through Cisco.com Search or in the Cisco Community