System Administration Guide: Devices and File Systems

Disk-Based File Systems

Disk-based file systems are stored on physical media such as hard disks, DVDs, and diskettes. Disk-based file systems can be written in different formats. The available formats are described in the following table.

Disk-Based File System 

Format Description 


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

Before you can create a UFS file system on a disk, you must format the disk and divide it into slices. For information on formatting disks and dividing disks into slices, see Chapter 10, Managing Disks (Overview).


The ZFS file system is available in the Solaris 10 6/06 release. For more information, see the Oracle Solaris ZFS Administration Guide.


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. When present on a CD-ROM, these extensions provide all UFS file system features and file types, except for writability and hard links.


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


The Universal Disk Format (UDFS) 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, as follows:

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

The Universal Disk Format (UDFS) File System

For information about creating a UDFS file system on removable media, see How to Create a File System on Removable Media.

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

The UDF file system is provided as dynamically loadable 32-bit and 64-bit modules, with system administration utilities for creating, mounting, and checking the file system on both SPARC and x86 platforms. The Solaris UDF file system works with supported ATAPI and SCSI DVD drives, CD-ROM devices, and disk and diskette drives. In addition, the Solaris UDF file system is fully compliant with the UDF 1.50 specification.

The UDF file system provides the following features:

The following features are not included in the UDF file system:

The UDF file system requires the following:

The Solaris UDF file system implementation provides the following: