MOUNT(8) BSD System Manager's Manual MOUNT(8) NNAAMMEE mmoouunntt, uummoouunntt - mount and dismount file systems SSYYNNOOPPSSIISS mmoouunntt [--aaffrrwwuu] [--tt _u_f_s | _l_f_s | _e_x_t_e_r_n_a_l___t_y_p_e] mmoouunntt [--ffrrwwuu] _s_p_e_c_i_a_l | _n_o_d_e mmoouunntt [--ffrrwwuu] [--tt _u_f_s | _l_f_s | _e_x_t_e_r_n_a_l___t_y_p_e] [--oo _o_p_t_i_o_n_s] _s_p_e_c_i_a_l _n_o_d_e uummoouunntt [--aaff] [--tt _u_f_s | _l_f_s | _e_x_t_e_r_n_a_l___t_y_p_e] uummoouunntt [--ff] _s_p_e_c_i_a_l | _n_o_d_e DDEESSCCRRIIPPTTIIOONN The mmoouunntt command calls the mount(2) system call to prepare and graft a _s_p_e_c_i_a_l device or the remote node (rhost:path) on to the file system tree at the point _n_o_d_e_. If either _s_p_e_c_i_a_l or _n_o_d_e are not provided, the appro- priate information is taken from the fstab(5) file. The system maintains a list of currently mounted file systems. If no ar- guments are given to mmoouunntt,, this list is printed. Options available for the mmoouunntt command: --FF The standard mount options are parsed and passed to external pro- gram via the --FF option as a decimal number. (See example below.) --dd Causes everything to be done except for the actual system call. This option is useful in conjunction with the --vv flag to deter- mine what the mmoouunntt command is trying to do. --ff Forces the revocation of write access when trying to downgrade a filesystem mount status from read-write to read-only. --oo Options are specified with a --oo flag followed by a comma separat- ed string of options. The following options apply to any file system that is being mounted: noexec Do not allow execution of any binaries on the mounted file system. This options is useful for a server that has file systems containing binaries for architectures other than its own. nosuid Do not allow set-user-identifier or set-group-identifier bits to take effect. nodev Do not interpret character or block special devices on the file system. This options is useful for a server that has file systems containing special devices for ar- chitectures other than its own. synchronous All I/O to the file system should be done synchronously. union Causes the namespace at the mount point to appear as the union of the mounted filesystem root and the existing di- rectory. Lookups will be done in the mounted filesystem first. If those operations fail due to a non-existent file the underlying directory is then accessed. All cre- ates are done in the mounted filesystem. --rr The file system object is to be mounted read-only. --tt _u_f_s | _l_f_s | _e_x_t_e_r_n_a_l _t_y_p_e The argument following the --tt is used to indicate the file system type. The type _u_f_s is the default. The _-_t option can be used to indicate that the actions should only be taken on filesystems of the specified type. More than one type may be specified in a comma separated list. The list of filesystem types can be pre- fixed with ``no'' to specify the filesystem types on which no ac- tion should be taken. For example, the mmoouunntt command: mount -a -t nonfs,mfs mounts all filesystems except those of type NFS and MFS. If the type is not one of the internally known types, mount will attempt to execute a program in _/_s_b_i_n_/_m_o_u_n_t___X_X_X where _X_X_X is re- placed by the type name. For example, nfs filesystems are mount- ed by the program _/_s_b_i_n_/_m_o_u_n_t___n_f_s. --uu The --uu flag indicates that the status of an already mounted file system should be changed. Any of the options discussed above (the --oo option) may be changed; also a file system can be changed from read-only to read-write or vice versa. An attempt to change from read-write to read-only will fail if any files on the filesystem are currently open for writing unless the --ff flag is also specified. The set of options is determined by first ex- tracting the options for the file system from the fstab table, then applying any options specified by the --oo argument, and fi- nally applying the --rr or --ww option. --vv Verbose mode. --ww The file system object is to be read and write. -- Any additional options specific to the program can be passed as a comma separated list; these options are distinguished by starting with a -- (dash). Those options that take a value are specified using the syntax -op- tion=value. For example, the mount command: mount -t mfs -o nosuid,-N,-s=4000 /dev/dk0b /tmp causes mount to attempt to execute: /sbin/mount_mfs -F 8 -N -s 4000 /dev/dk0b /tmp The options specific to NFS filesystems are described in the mount_nfs(8) manual page. UUmmoouunntt removes the _s_p_e_c_i_a_l device grafted at point _n_o_d_e from file system tree. Options for the uummoouunntt command: --ff The file system is forcibly unmounted. Active special devices continue to work, but all other files return errors if further accesses are attempted. The root file system cannot be forcibly unmounted. --aa All of the file systems described in fstab(5) are unmounted. --tt Is used to indicate the actions should only be taken on filesys- tems of the specified type. More than one type may be specified in a comma separated list. The list of filesystem types can be prefixed with ``no'' to specify the filesystem types on which no action should be taken. (See example above for the mmoouunntt com- mand.) FFIILLEESS /etc/fstab file system table SSEEEE AALLSSOO mount(2), unmount(2), fstab(5) BBUUGGSS It is possible for a corrupted file system to cause a crash. HHIISSTTOORRYY A mmoouunntt command appeared in Version 6 AT&T UNIX. 4th Berkeley Distribution July 11, 1993 3