About rules for moving volumes between groups
The following are the rules for moving volumes between groups:
The target volume group must contain the same type of media as the source volume group. If the target volume group is empty: The successive volumes that you add to it must match the type of media that you first add to it.
All volumes in a robotic library must belong to a volume group. If you do not specify a group, NetBackup generates a new volume group name by using the robot number and type.
More than one volume group can share the same location. For example, a robotic library can contain volumes from more than one volume group and you can have more than one standalone volume group.
All members of a group must be in the same robotic library or be standalone. That is, if volume group already exists in another robotic library, you cannot add it (or part of it) to a robotic library.