System Administration Guide: Basic Administration

The Default Solaris File Systems

The Solaris UFS file system is hierarchical, starting with the root directory (/) and continuing downwards through a number of directories. The Solaris installation process enables you to install a default set of directories and uses a set of conventions to group similar types of files together. The following table provides a summary of the default Solaris file systems.

Table 37–2 The Default Solaris File Systems

File System or Directory 

File System Type 

Description 

root (/)

UFS 

The top of the hierarchical file tree. The root directory contains the directories and files that are critical for system operation, such as the kernel, the device drivers, and the programs used to boot the system. The root directory also contains the mount point directories where local and remote file systems can be attached to the file tree. 

/usr

UFS 

System files and directories that can be shared with other users. Files that run only on certain types of systems are in the /usr file system (for example, SPARC executables). Files that can be used on all types of systems, such as the man pages, are in the /usr/share directory.

/export/home or /home

NFS, UFS 

The mount point for users' home directories, which store user work files. By default the /home directory is an automounted file system. On standalone systems, the /home directory might be a UFS file system on a local disk slice.

/var

UFS 

System files and directories that are likely to change or grow over the life of the local system. These include system logs, vi and ex backup files, and uucp files.

/opt

NFS, UFS 

Optional mount point for third-party software. On some systems, the /opt directory might be a UFS file system on a local disk slice.

/tmp

TMPFS 

Temporary files, which are cleared each time the system is booted or the /tmp file system is unmounted.

/proc

PROCFS 

A list of active processes, by number. 

/etc/mnttab

MNTFS 

A file system that provides read-only access to the table of mounted file systems for the local system. 

/var/run

TMPFS 

A file system for storing temporary files that are not needed after the system is booted. 

The root (/) and /usr file systems are needed to run a system. Some of the most basic commands in the /usr file system (like mount) are included in the root (/) file system so that they are available when the system boots or is in single-user mode and /usr is not mounted. For more detailed information on the default directories for the root (/) and /usr file systems, see Chapter 43, UFS File System (Reference).