Extended fundamental types (EFT) 

Provides 32-bit user ID (UID), group ID (GID), and device numbers.

Large file systems 

Allows files of about 1 terabyte in size in a file system that can be up to 16 terabytes in size. You can create a multiterabyte UFS file system on a disk with an EFI disk label.

Logging 

UFS logging bundles the multiple metadata changes that comprise a complete UFS operation into a transaction. Sets of transactions are recorded in an on-disk log and are applied to the actual UFS file system's metadata. 

Multiterabyte file systems 

A multiterabyte file system enables creation of a UFS file system up to approximately 16 terabytes of usable space, minus approximately one percent overhead.

State flags 

Shows the state of the file system: clean, stable, active, logging, or unknown. These flags eliminate unnecessary file system checks. If the file system is “clean,” “stable,” or “logging,” file system checks are not run.