The short answer is “yes it is”. Without it, it will not be poosible to fully recover the host from the DR backup.
It is important that all the VSS, SYSTEM STATE and DISASTER_RECOVERY components are
selected for a NetWorker™ DR backup. The actual saveset name varies according to the Windows OS type and EMC NetWorker™ client version being used.
For example, the diagram below shows the EMC NetWorker™ user client configured to backup all VSS and Disaster Recovery components on Windows 2008 R2 with client version 8.2.0.
Ensure you do not select any CD/DVD or floppy drives for the backup.
As long as the NBMR configuration has been created (see NBMR User Guide) and a full VSS EMC NetWorker™ backup is performed afterwards, then it will be possible to recover the system using the NBMR DR environment.