A system administrator notices low storage space on a file server. What should be implemented to limit users' storage space?

Implementing a disk quota is an effective way to limit users' storage space on a file server. Disk quotas allow system administrators to set specific limits on the amount of storage each user can use on a disk volume. By enforcing these limits, administrators can manage storage resources more efficiently and prevent any single user from monopolizing disk space, thereby ensuring that the available storage is equitably distributed among all users.

When quotas are applied, users receive notifications when they are approaching their limit and are unable to save more data once they reach it. This proactive management encourages users to monitor their storage usage and delete unnecessary files. It also helps maintain the overall health of the file server by preventing excessive consumption of storage resources.

Regarding the other options, while disk shadowing, disk compression, and disk indexing each have their merits in regard to data storage and management, they do not specifically address the need to limit the amount of storage space that can be utilized by users. Disk shadowing is primarily for data redundancy, disk compression helps save space but does not control individual user limits, and disk indexing is used to enhance the speed of file searches rather than manage storage allocation.