mount(8) — Maintenance
OSF — Environment_Note_Added
NAME
mount, umount − Mounts and dismounts file systems
SYNOPSIS
mount
mount -a [-v] [-t type]
mount [-rv] [-o option, ...] [-t type] file_system directory
mount [-v] file_system
mount [-v] directory
umount [-h host]
umount -a [-v] [-t type]
umount [-v] file_system | directory ...
FLAGS
mount Flags
-aAttempts to mount all the file systems described in /etc/fstab. In this case, file_system and directory are taken from /etc/fstab. If a type is specified, all of the file systems in /etc/fstab with that type will be mounted. File systems are not necessarily mounted in the order listed in /etc/fstab.
-o option[,option ...]
Specifies a list of comma-separated options from the following list. Some options are valid for all file system types, while others apply to a specific type only. The following options are valid on all file systems. The default is rw,noquota:
quotaUsage limits enforced.
noquotaUsage limits not enforced.
rwRead/write.
roRead-only.
suidSet-user-ID execution allowed.
nosuidSet-user-ID execution not allowed.
The following options are specific to nfs (NFS) file systems:
bgIf the first mount attempt fails, retries in the background.
fgRetries in foreground.
retry=nSets the number of mount failure retries to n.
rsize=nSets the read buffer size to n bytes.
wsize=nSets the write buffer size to n bytes.
timeo=nSets the NFS time-out to n tenths of a second.
retrans=nSets the number of NFS retransmissions to n.
port=nSets the server IP port number to n.
softReturns an error if the server does not respond.
hardRetries request until the server responds.
The defaults are fg,retry=10000,timeo=10,retrans=10,port=NFS_PORT,hard. Defaults for rsize and wsize are set by the kernel. The bg option causes mount to run in the background if the server’s mountd does not respond. mount attempts each request retry=n times before giving up. Once the file system is mounted, each NFS request made in the kernel waits timeo=n tenths of a second for a response. If no response arrives, the time-out is multiplied by 2 and the request is retransmitted. When retrans=n retransmissions have been sent with no reply, a soft mounted file system returns an error on the request and a hard mounted file system retries the request. File systems that are mounted rw (read/write) should use the hard option. The number of bytes in a read or write request can be set with the rsize and wsize options.
-rMounts the specified file system read-only. This is a shorthand for the following:
mount -o ro file_system directory
Physically write-protected and magnetic tape file systems must be mounted read-only, or errors will occur when access times are updated, whether or not any explicit write is attempted.
-t typeSpecifies the file system type. The accepted types are:
•ufs
•s5fs
•nfs
•mfs
See fstab(4) for a description of the legal file system types.
-vDisplays a message indicating which file system is being mounted (verbose).
umount Flags
-aAttempts to unmount all the file systems currently mounted (listed in /etc/fstab). In this case, file_system is taken from /etc/fstab.
-h hostUnmounts all file systems listed in /etc/fstab that are remotely mounted from host.
-t typeUnmounts all file systems listed in /etc/fstab that are of the specified type.
-vDisplays a message indicating the file system being unmounted (verbose).
DESCRIPTION
The mount command announces to the system that a file system, file_system, is to be attached to the file tree at directory, which must already exist. It becomes the name of the newly mounted root. The contents of directory are hidden until the file system is unmounted. If file_system is of the form host:path, the file system type is assumed to be Network File System (NFS).
The umount command announces to the system that the file system, file_system, previously mounted on directory should be removed. Either the file system name or the mounted-on directory may be used.
If invoked with only one of file_system or directory, mount searches /etc/fstab for an entry whose directory or file_system field matches the given argument. For example, mount /usr and mount /dev/xy0g are shorthand for mount /dev/xy0g /usr if the following line is in /etc/fstab:
/dev/xy0g /usr ufs rw 1 1
EXAMPLES
1.To mount a local disk, enter:
mount /dev/xy0g /usr
2.To mount all ufs file systems, enter:
mount -at ufs
3.To mount a remote file system, enter:
mount -t nfs serv:/usr/src /usr/src
4.To mount a remote file system, enter:
mount serv:/usr/src /usr/src
5.To mount remote file system with a hard mount, enter:
mount -o hard serv:/usr/src /usr/src
FILES
/usr/sbin/mount
Specifies the command path
/usr/sbin/umount
Specifies the command path
/etc/fstab
NOTES
No more than one user should mount a disk partition read/write or the file system may become corrupted.
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 being mounted on top of the symbolic link itself.
ENVIRONMENT NOTES
This section describes system features that are not generic to OSF/1 but that are provided in this OSF/1 implementation.
ULTRIX Compatibility
FLAGS
mount Flags
The following options are specific to cdfs (CDFS) file systems.
defpermIgnores these permissions bits, if present, and defaults all file and directory permissions to the value 0666, with a zero UID (owned by root). Files and directories recorded on an ISO 9660 formatted file system may or may not have permission bits. This is a default option since the permissions on most of the existing ISO 9660 formatted CD-ROM’s do not map into the UID scheme that is used.
nodefpermUses the on-disk permission bits, if present. If a file or directory is not recorded with permissions bits, the 0666 default is used.
noversionStrips off the ’;#’ extension off the version string, if a file recorded on an ISO 9660 formatted file system contains a version string. Use this option if you are mounting a CD-ROM containing MS-DOS applications.
The defaults are ro, defperm.
The following options affect how quickly you see updates to a file or directory that has been modified by another host. Increasing these values will give you slightly better performance. Decreasing these values decreases the time it takes for you to see modifications made on another host. If you are the only person modifying files under this mount point, increase these values.
acdirmin=Vn
Hold cached directory attributes for at least n seconds.
acdirmax=Vn
Hold cached directory attributes for no more than n seconds. The maximum value is 3600.
acregmin=Vn
Hold cached file attributes for at least n seconds.
acregmax=Vn
Hold cached file attributes for no more than n seconds. The maximum value is 3600.
actimeo=Vn
Set all four attributes’ cache timeout values to n.
noacDo not set attribute caching. This is equivalent to actimeo=0.
noctoDo not get a fresh attribute when opening a file.
The defaults are acdirmin=30, acdirmax=60, acregmin=3, acregmax=60.
-t typeSpecifies the file system type. Additional type is:
•cdfs
DESCRIPTION
The mount command also allows you to mount an ISO 9660 or High Sierra (HSG) formatted file system onto a directory.
EXAMPLES
1.To mount an ISO 9660 or HSG formatted file system on the block device /dev/rz3c onto the local directory /cdfs with the file version strings stripped off, enter:
mount -t cdfs -o noversion /dev/rz3c /cdfs
NOTES
If mounting of an ISO 9660 or HSG volume fails with
cdfs_mount: Operation Not Supported
refer to the cdfs(4) reference page for information on the correct system configuration options to set before using CDFS.
Digital Extensions
SYNOPSIS
mount [-l] [-d] [-f] [-u]
FLAGS
-lDisplays the value of all file system options.
-dMounts a CDrom UFS file system.
-fPerforms a "fake" mount and does not actually mount the file system.
-uMounts the specified file system read-write.
SYNOPSIS
umount [-f]
FLAGS
-fPerforms a fast unmount that causes only remote file systems to be unmounted without notifying the server.
RELATED INFORMATION
Functions: mount(3), umount(3).
Files: fstab(4).