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SunOS man pages : mount_ufs (1)

Maintenance Commands                                mount_ufs(1M)


mount_ufs - mount ufs file systems


mount -F ufs [ generic_options ] [ -o specific_options ] [ -O ] special | mount_point mount -F ufs [ generic_options ] [ -o specific_options ] [ -O ] special mount_point


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). 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.


See mount(1M) for the list of supported generic_options. The following options are supported: -o specific_options Specify ufs file system specific options in a comma-separated list with no intervening spaces. If invalid options are specified, a warning mes- sage is printed and the invalid options are ignored. The following options are available: noatime 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 SunOS 5.8 Last change: 9 May 1999 1 Maintenance Commands mount_ufs(1M) Usenet news spool). noatime turns off access time recording regardless of dfratime or nodfratime. dfratime | nodfratime 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. forcedirectio | noforcedirectio If forcedirectio is specified and sup- ported 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 per- formance option that benefits only from large sequential data transfers. The default behavior is noforcedirectio. global | noglobal 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 clus- ter. If noglobal is specified, the mount will not be globally visible. The default behavior is noglobal. intr|nointr 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. largefiles | nolargefiles If nolargefiles is specified and supported by the file system, then for the duration of the mount it is guaranteed that all reg- ular files in the file system have a size that will fit in the smallest object of type off_t supported by the system perform- ing the mount. The mount will fail if there are any files in the file system not SunOS 5.8 Last change: 9 May 1999 2 Maintenance Commands mount_ufs(1M) 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. logging | nologging 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 sys- tem later. This prevents file systems from becoming inconsistent, therefore eliminat- ing 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 continu- ally 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. m Mount the file system without making an SunOS 5.8 Last change: 9 May 1999 3 Maintenance Commands mount_ufs(1M) entry in /etc/mnttab. onerror=action 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. quota Quotas are turned on for the file system. remount 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. rq Read-write with quotas turned on. Equivalent to rw, quota. ro | rw Read-only or read-write. Default is rw. suid | nosuid Allow or disallow setuid execution. The default is suid. This option can also be used when mounting devices. -O 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".


/etc/mnttab table of mounted file systems /etc/vfstab list of default parameters for each file system


SunOS 5.8 Last change: 9 May 1999 4 Maintenance Commands mount_ufs(1M) See attributes(5) for descriptions of the following attri- butes: ____________________________________________________________ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | |_____________________________|_____________________________| | Availability | SUNWcsu | |_____________________________|_____________________________|


fsck(1M), fsck_ufs(1M), mount(1M), mountall(1M), mount(2), stat(2), mnttab(4), vfstab(4), attributes(5), largefile(5)


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. SunOS 5.8 Last change: 9 May 1999 5