protect

This attribute specifies the number of clients that can simultaneously access the volume. It refuses access to additional clients. Attachments count cumulatively for all realms, and a count of 0 denies all access to the volume. If the volume lies within another volume, it appears empty when a client tries to access it through the volume in which it lies. No volumes may coincide with or lie within a protected volume. This attribute helps administrators comply with software licenses. It does not support escape sequences for its path.

Usage:

tnvolume -M -v volume -a protect=limit