System Administration Guide, Volume 1

Commonly Used Mount Options

The table below describes the commonly used mount options that you can specify with the -o option of the mount command. If you specify multiple options, separate them with commas (no spaces). For example, -o ro,nosuid.

For a complete list of mount options for each file system type, refer to the specific mount command man pages (for example, mount_ufs(1M)).

Table 36-3 Commonly Used -o Mount Options


File System 


bg | fg


If the first attempt fails, retries in the background (bg) or in the foreground (fg). This option is safe for non-critical vfstab entries. The default is fg.

hard | soft


Specifies the procedure if the server does not respond. soft indicates that an error is returned. hard indicates that the retry request is continued until the server responds. The default is hard.

intr | nointr


Specifies whether keyboard interrupts are delivered to a process that is hung while waiting for a response on a hard-mounted file system. The default is intr (interrupts allowed).

largefiles | nolargefiles


Enables you to create files larger than 2 Gbytes. The largefiles option means that a file system mounted with this option might contain files larger than 2 Gbytes, but it is not a requirement. The default is largefiles. If the nolargefiles option is specified, the file system could not be mounted on a system running Solaris 2.6 or compatible versions.

logging | nologging


Enables logging for the file system. UFS logging is the process of storing transactions (changes that make up a complete UFS operation) into a log before the transactions are applied to the UFS file system. Logging helps prevent UFS file systems from becoming inconsistent, which means fsck can be bypassed. Bypassing fsck reduces the time to reboot a system if it crashes, or after a system is shutdown uncleanly.

The log is allocated from free blocks on the file system, and is sized approximately 1 Mbyte per 1 Gbyte of file system, up to a maximum of 64 Mbytes. The default is nologging.



Suppresses access time updates on files, except when they coincide with updates to the ctime or mtime. See stat(2). This option reduces disk activity on file systems where access times are unimportant (for example, a Usenet news spool). The default is normal access time (atime) recording.



Changes the mount options associated with an already-mounted file system. This option can generally be used with any option except ro, but what can be changed with this option is dependent on the file system type.



Retries the mount operation when it fails. n is the number of times to retry.

ro | rw


Specifies read/write or read-only. If you do not specify this option, the default is read/write. The default option for HSFS is ro.

suid | nosuid


Allows or disallows setuid execution. The default is to allow setuid execution.