System Administration Guide, Volume 1

Disk-Based File Systems

Disk-based file systems are stored on physical media such as hard disks, CD-ROMs, and diskettes. Disk-based file systems can be written in different formats. The available formats are:

Disk-Based File System  

Format Description 


UNIX file system (based on the BSD Fast File system that was provided in the 4.3 Tahoe release). UFS is the default disk-based file system for the Solaris operating environment.

Before you can create a UFS file system on a disk, the disk must be formatted and divided into slices. See Chapter 28, Disk Management (Overview) for complete information on formatting disks and dividing disks into slices.


High Sierra, Rock Ridge, and ISO 9660 file system. High Sierra is the first CD-ROM file system; ISO 9660 is the official standard version of the High Sierra File System. The HSFS file system is used on CD-ROMs, and is a read-only file system. Solaris HSFS supports Rock Ridge extensions to ISO 9660, which, when present on a CD-ROM, provide all UFS file system features and file types except for writability and hard links.


PC file system, which allows read/write access to data and programs on DOS-formatted disks written for DOS-based personal computers.


The UDF file system, the industry-standard format for storing information on the optical media technology called DVD (Digital Versatile Disc or Digital Video Disc).  

Each type of disk-based file system is customarily associated with a particular media device:

These associations are not, however, restrictive. For example, CD-ROMs and diskettes can have UFS file systems created on them.