The mount utility attaches a ufs file system to the file system hierarchy at the mount_point, which is the pathname of a directory. If mount_point has any contents prior to the mount operation, these are hidden until the file system is unmounted.
If mount is invoked with special or mount_point as the only arguments, mount will search /etc/vfstab to fill in the missing arguments, including the specific_options. See mount(1M) for more details.
If special and mount_point are specified without any specific_options, the default is rw.
If the directory on which a file system is to be mounted is a symbolic link, the file system is mounted on the directory to which the symbolic link refers, rather than on top of the symbolic link itself.
Security attributes can be specified at mount time, with the -o or -S option on the mount command line or in the vfstab_adjunct(4) file. See the DESCRIPTION in the mount(1M) man page for more about specifying security attributes.
Except when merely listing mounted file systems and resources, mount must run with the
To succeed in all cases, mount needs:
When mounting a UFS file system, mount should assert the
sys_fs_config privilege. Otherwise, the mount succeeds, but logging
is not enabled/disabled, errno is set to EPERM, and the user sees an error message.
See mount(1M) for the list of supported generic_options.
Specify ufs file system specific options in a comma-separated list with no intervening spaces. Most attributes for the -S option may also be specified for the -o option. See the -S option.
By default, the file system is mounted with normal access time (atime) recording. If noatime is specified, the file system will ignore 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).
noatime turns off access time recording regardless of dfratime or nodfratime.
Allow (disallow) opens on character and block devices. The default is devices.
Note: In the Trusted Solaris environment, device special files are typically located only in the /dev and /devices directories in the root file system. All other file systems should be mounted with the nodevices option to prevent recognition of devices that may reside in any other directories.
By default, writing access time updates to the disk may be deferred (dfratime) for the file system until the disk is accessed for a reason other than updating access times. nodfratime disables this behavior.
Fake an /etc/mnttab entry, but do not actually mount any file systems. Parameters are not verified.
If forcedirectio is specified and supported by the file system, then for the duration of the mount forced direct I/O will be used. If the filesystem is mounted using forcedirectio, then data is transferred directly between user address space and the disk. If the filesystem is mounted using noforcedirectio, then data is buffered in kernel address space when data is transferred between user address space and the disk. forcedirectio is a performance option that benefits only from large sequential data transfers. The default behavior is noforcedirectio.
If global is specified and supported on the file system, and the system in question is part of a cluster, the file system will be globally visible on all nodes of the cluster. If noglobal is specified, the mount will not be globally visible. The default behavior is noglobal.
Allow (do not allow) keyboard interrupts to kill a process that is waiting for an operation on a locked file system. The default is intr.
If nolargefiles is specified and supported by the file system, then for the duration of the mount it is guaranteed that all regular files in the file system have a size that will fit in the smallest object of type off_t supported by the system performing the mount. The mount will fail if there are any files in the file system not meeting this criterion. If largefiles is specified, there is no such guarantee. The default behavior is largefiles.
If nolargefiles is specified, mount will fail for ufs if the file system to be mounted has contained a large file (a file whose size is greater than or equal to 2 Gbyte) since the last invocation of fsck on the file system. The large file need not be present in the file system at the time of the mount for the mount to fail; it could have been created previously and destroyed. Invoking fsck (see fsck_ufs(1M)) on the file system will reset the file system state if no large files are present. After invoking fsck, a successful mount of the file system with nolargefiles specified indicates the absence of large files in the file system; an unsuccessful mount attempt indicates the presence of at least one large file.
If logging is specified, then logging is enabled for the duration of the mounted file system. Logging is the process of storing transactions (changes that make up a complete UFS operation) in a log before the transactions are applied to the file system. Once a transaction is stored, the transaction can be applied to the file system later. This prevents file systems from becoming inconsistent, therefore eliminating the need to run fsck. And, because fsck can be bypassed, logging reduces the time required to reboot a system if it crashes, or after an unclean halt. The default behavior is nologging.
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. Logging can be enabled on any UFS, including root (/). The log created by UFS logging is continually flushed as it fills up. The log is totally flushed when the file system is unmounted or as a result of the lockfs -f command.
Mount the file system without making an entry in /etc/mnttab.
This option specifies the action that UFS should take to recover from an internal inconsistency on a file system. Specify action as panic, lock, or umount. These values cause a forced system shutdown, a file system lock to be applied to the file system, or the file system to be forcibly unmounted, respectively. The default is panic.
Forced privileges on executables are allowed or disallowed. The default is priv.
This option is not supported in Trusted Solaris; any attempt to set this option is ignored. Quotas are turned on for the file system.
Remounts a read-only file system as read-write (using the rw option). This option can be used only in conjunction with the f, logging|nologging, m, and noatime options. This option works only on currently mounted read-only file systems.
Read-write with quotas turned on. Equivalent to rw, quota.
Read-only or read-write. Default is rw.
Allow or disallow setuid execution. The default is suid. This option can also be used when mounting devices.
Overlay mount. Allow the file system to be mounted over an existing mount point, making the underlying file system inaccessible. If a mount is attempted on a pre-existing mount point without setting this flag, the mount will fail, producing the error “device busy”.
See the definition of the -S option in the OPTIONS section of the mount(1M) man page.
Table of mounted file systems
List of default parameters for each file system
Mount-time attributes for file systems
See attributes(5) for descriptions of the following attributes:
The -o quota option has been removed; the nodevices and nopriv options have been added.
Mount-time security attributes can be specified for file systems whose objects do not have any attributes (such as user and group IDs) and for file systems that do not have the Trusted Solaris extended security attributes (such as sensitivity labels). Trusted Solaris security policy applies when mounting.
mount must run with the
To succeed in all cases, the mount command needs the privileges:
When mounting a UFS file system, mount should assert the
sys_fs_config privilege. Otherwise, the mount succeeds, but logging is not enabled/disabled, errno is set to EPERM, and
the user sees an error message.
Since the root (/) file system is mounted read-only by the kernel during the boot process, only the remount option (and options that can be used in conjunction with remount) affect the root (/) entry in the /etc/vfstab file.