IRIX Base Documentation 2002 November

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AAAAUUUUTTTTOOOOMMMMOOOOUUUUNNNNTTTT((((1111MMMM)))) AAAAUUUUTTTTOOOOMMMMOOOOUUUUNNNNTTTT((((1111MMMM)))) NNNNAAAAMMMMEEEE automount - automatically mount NFS filesystems SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS ////uuuussssrrrr////eeeettttcccc////aaaauuuuttttoooommmmoooouuuunnnntttt [ ----mmmmnnnnTTTTvvvv ] [ ----DDDD _n_a_m_e=_v_a_l_u_e ] [ ----ffff _m_a_s_t_e_r-_f_i_l_e ] [ ----pppp _p_r_i_o_r_i_t_y ] [ ----MMMM _m_o_u_n_t-_d_i_r_e_c_t_o_r_y ] [ ----ttttllll _d_u_r_a_t_i_o_n ] [ ----ttttmmmm _i_n_t_e_r_v_a_l ] [ ----ttttpppp _d_u_r_a_t_i_o_n ] [ ----ttttwwww _i_n_t_e_r_v_a_l ] [ _d_i_r_e_c_t_o_r_y _m_a_p_n_a_m_e [ -_m_o_u_n_t-_o_p_t_i_o_n_s ] ] ... DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN _A_u_t_o_m_o_u_n_t is a daemon that automatically and transparently mounts NFS filesystems as needed. Whenever a user on a client machine running _a_u_t_o_m_o_u_n_t invokes a command that needs to access a remote file or directory, the hierarchy to which that file or directory belongs is mounted and remains mounted for as long as it is needed. When a certain amount of time has elapsed during which the hierarchy is not accessed, it is automatically unmounted. No mounting of unaccessed remote filesystems is done at boot-time, and the user doesn't need special privilege to mount a directory. The _a_u_t_o_m_o_u_n_t daemon is started during system initialization from the /_e_t_c/_i_n_i_t._d/_n_e_t_w_o_r_k script if the configuration flags ``nfs'' and ``automount'' are set ``on.'' Do the following commands as super-user to enable _a_u_t_o_m_o_u_n_t: /etc/chkconfig nfs on /etc/chkconfig automount on Rebooting will start _a_u_t_o_m_o_u_n_t with the options and arguments contained in the file /_e_t_c/_c_o_n_f_i_g/_a_u_t_o_m_o_u_n_t._o_p_t_i_o_n_s. The default version of this file lets you access exported directories on another host with the filename prefix of /hosts/<_h_o_s_t_n_a_m_e>/ For example, if host _s_p_r_i_n_g_f_i_e_l_d exports /_u_s_r, then ls /hosts/springfield/usr will show the contents of that directory. You may want to customize this file for your site. Unlike _m_o_u_n_t, _a_u_t_o_m_o_u_n_t does not consult the file /_e_t_c/_f_s_t_a_b for a list of hierarchies to mount. Rather, it consults a series of maps, which can be either direct or indirect. The names of the maps can be passed to _a_u_t_o_m_o_u_n_t from the command line (via the /_e_t_c/_c_o_n_f_i_g/_a_u_t_o_m_o_u_n_t._o_p_t_i_o_n_s file), or from another (_m_a_s_t_e_r) map. The master map lists (as if from the command line) all other maps, applicable options, and mount points. PPPPaaaaggggeeee 1111 AAAAUUUUTTTTOOOOMMMMOOOOUUUUNNNNTTTT((((1111MMMM)))) AAAAUUUUTTTTOOOOMMMMOOOOUUUUNNNNTTTT((((1111MMMM)))) An indirect map allows you to specify mappings for the subdirectories you wish to mount under the _d_i_r_e_c_t_o_r_y indicated on the command line. In an indirect map, each _d_i_r_e_c_t_o_r_y field consists of the basename of a subdirectory to be mounted as needed. A direct map contains mappings for any number of directories. Each directory listed in the map is automatically mounted as needed. The direct map as a whole is not associated with any single directory. _a_u_t_o_m_o_u_n_t appears to be an NFS server to the kernel. _a_u_t_o_m_o_u_n_t uses the map contained in the _m_a_p_n_a_m_e argument to locate an appropriate NFS file server, exported filesystem, and mount options. It then mounts the filesystem in a temporary location, and creates a symbolic link to the temporary location. If the filesystem is not accessed within an appropriate interval (five minutes by default), the daemon unmounts the filesystem and removes the symbolic link. If the indicated directory has not already been created, the daemon creates it, and then removes it upon exiting. By default, _a_u_t_o_m_o_u_n_t mounts everything under the directory /_t_m_p__m_n_t. For instance, if a user wants to mount a remote directory _s_r_c under /_u_s_r/_s_r_c, the actual mount point will be /_t_m_p__m_n_t/_u_s_r/_s_r_c, and /_u_s_r/_s_r_c will be a symbolic link to that location. As with any other kind of mount, a mount effected through the automounter on a non-empty mount point will hide the original contents of the mount point for as long as the mount is in effect. Since the name-to-location binding is dynamic, updates to an _a_u_t_o_m_o_u_n_t map are transparent to the user. This obviates the need to ``pre-mount'' shared file systems for applications that have ``hard-coded'' references to files. Nor is there a need to maintain records of which hosts must be mounted for what applications. If the _d_i_r_e_c_t_o_r_y argument is a pathname, the _m_a_p argument points to an _i_n_d_i_r_e_c_t map. An indirect map contains a list of the subdirectories contained within the indicated _d_i_r_e_c_t_o_r_y. With an indirect map, it is these subdirectories that are mounted automatically. If the _d_i_r_e_c_t_o_r_y argument is `/-', _a_u_t_o_m_o_u_n_t treats the _m_a_p argument that follows as the name of a _d_i_r_e_c_t map. In a direct map, each entry associates the full pathname of a mount point with a remote filesystem to mount. A map can be a file or a network information service (NIS) map; if a file, the _m_a_p argument must be a full pathname. The -_m_o_u_n_t-_o_p_t_i_o_n_s argument, when supplied, consists of the leading dash and a comma-separated list of options to _m_o_u_n_t(1M), as described in _f_s_t_a_b(4). If these options are supplied, they become the default mount options for all entries in the map. Mount options provided within a map entry override these defaults. PPPPaaaaggggeeee 2222 AAAAUUUUTTTTOOOOMMMMOOOOUUUUNNNNTTTT((((1111MMMM)))) AAAAUUUUTTTTOOOOMMMMOOOOUUUUNNNNTTTT((((1111MMMM)))) OOOOPPPPTTTTIIIIOOOONNNNSSSS ----DDDD _v_a_r=_v_a_l_u_e Assign _v_a_l_u_e to the indicated automount (environment) variable. ----ffff _m_a_s_t_e_r-_f_i_l_e Read a local file for initialization, before reading the _a_u_t_o._m_a_s_t_e_r NIS map. The information in _m_a_s_t_e_r-_f_i_l_e will take precedence. ----mmmm Suppress initialization of _d_i_r_e_c_t_o_r_y-_m_a_p_n_a_m_e pairs listed in the _a_u_t_o._m_a_s_t_e_r NIS database. ----MMMM _m_o_u_n_t-_d_i_r_e_c_t_o_r_y Mount temporary filesystems in the named directory, instead of /_t_m_p__m_n_t. ----nnnn Disable dynamic mounts. With this option, references through the _a_u_t_o_m_o_u_n_t daemon only succeed when the target filesystem has been previously mounted. This can be used to prevent NFS servers from cross-mounting each other. ----TTTT Trace. Expand each NFS call and display it on standard error. ----pppp _p_r_i_o_r_i_t_y Set the (non-degrading) priority of the automount process. The default is NDPNORMAX (40). ----ttttllll _d_u_r_a_t_i_o_n Specify a _d_u_r_a_t_i_o_n, in seconds, that a filesystem is to remain mounted when not in use. The default is 300 seconds (5 minutes). ----ttttmmmm _i_n_t_e_r_v_a_l Specify an _i_n_t_e_r_v_a_l, in seconds, between attempts to mount a filesystem. The default is 30 seconds. ----ttttpppp _d_u_r_a_t_i_o_n Specify the _d_u_r_a_t_i_o_n, in seconds, that the results of a probe of a server's availability will remain cached. The default is 5 seconds. ----ttttwwww _i_n_t_e_r_v_a_l Specify an _i_n_t_e_r_v_a_l, in seconds, between attempts to unmount filesystems that have exceeded their cached times. The default is 60 seconds. ----vvvv Verbose. Log status and/or warning messages through _s_y_s_l_o_g(3B) or to the console. EEEENNNNVVVVIIIIRRRROOOONNNNMMMMEEEENNNNTTTT Environment variables can be used within an automount map. For instance, if $HOME appeared within a map, _a_u_t_o_m_o_u_n_t would expand it to its current value for the HOME variable. Environment variables are expanded only for the automounter's environment - not for the environment of a user using the automounter's services. PPPPaaaaggggeeee 3333 AAAAUUUUTTTTOOOOMMMMOOOOUUUUNNNNTTTT((((1111MMMM)))) AAAAUUUUTTTTOOOOMMMMOOOOUUUUNNNNTTTT((((1111MMMM)))) If a variable reference needs to be protected from affixed characters, you can surround the variable name with curly braces. UUUUSSSSAAAAGGGGEEEE MMMMaaaapppp EEEEnnnnttttrrrryyyy FFFFoooorrrrmmmmaaaatttt A simple map entry (mapping) takes the form: _d_i_r_e_c_t_o_r_y [ ----_m_o_u_n_t-_o_p_t_i_o_n_s ] _l_o_c_a_t_i_o_n ... where _d_i_r_e_c_t_o_r_y is the full pathname of the directory to mount when used in a direct map, or the basename of a subdirectory in an indirect map. _m_o_u_n_t-_o_p_t_i_o_n_s is a comma-separated list of options to _m_o_u_n_t(1M), as described in _f_s_t_a_b(4), and _l_o_c_a_t_i_o_n specifies a remote filesystem from which the directory may be mounted. In the simple case, _l_o_c_a_t_i_o_n takes the form: _h_o_s_t_n_a_m_e:_p_a_t_h_n_a_m_e _R_e_p_l_i_c_a_t_e_d _F_i_l_e_s_y_s_t_e_m_s Multiple _l_o_c_a_t_i_o_n fields can be specified for replicated read-only filesystems, in which case _a_u_t_o_m_o_u_n_t sends multiple mount requests; _a_u_t_o_m_o_u_n_t mounts the filesystem from the first host that replies to the mount request. This request is first made to the local net or subnet. If there is no response, any connected server may respond. Since _a_u_t_o_m_o_u_n_t does not monitor the status of the server while the filesystem is mounted, it will not use another location in the list if the currently mounted server crashes. This support for replicated filesystems is available only at mount time. Once unmounted, another location may be used for subsequent mounts of the filesystem. If each _l_o_c_a_t_i_o_n in the list shares the same _p_a_t_h_n_a_m_e then a single _l_o_c_a_t_i_o_n may be used with a comma-separated list of hostnames: _h_o_s_t_n_a_m_e_1,_h_o_s_t_n_a_m_e_2:_p_a_t_h_n_a_m_e _S_h_a_r_i_n_g _M_o_u_n_t_s If _l_o_c_a_t_i_o_n is specified in the form: _h_o_s_t_n_a_m_e:_p_a_t_h_n_a_m_e:_s_u_b_d_i_r _h_o_s_t_n_a_m_e is the name of the server from which to mount the filesystem, _p_a_t_h_n_a_m_e is the pathname of the directory to mount, and _s_u_b_d_i_r, when supplied, is the name of a subdirectory to which the symbolic link is made. This can be used to prevent duplicate mounts when multiple directories in the same remote filesystem may be accessed. With an indirect map for /_h_o_m_e such as: bart springfield:/home/simpsons:bart maggie springfield:/home/simpsons:maggie and a user attempting to access a file in /_h_o_m_e/_b_a_r_t, _a_u_t_o_m_o_u_n_t mounts _s_p_r_i_n_g_f_i_e_l_d:/_h_o_m_e/_s_i_m_p_s_o_n_s, but creates a symbolic link called /_h_o_m_e/_b_a_r_t PPPPaaaaggggeeee 4444 AAAAUUUUTTTTOOOOMMMMOOOOUUUUNNNNTTTT((((1111MMMM)))) AAAAUUUUTTTTOOOOMMMMOOOOUUUUNNNNTTTT((((1111MMMM)))) to the _b_a_r_t subdirectory in the temporarily-mounted filesystem. If a user immediately tries to access a file in /_h_o_m_e/_m_a_g_g_i_e, _a_u_t_o_m_o_u_n_t needs only to create a symbolic link that points to the _m_a_g_g_i_e subdirectory; /_h_o_m_e/_s_i_m_p_s_o_n_s is already mounted. With the following map: bart springfield:/home/simpsons/bart maggie springfield:/home/simpsons/maggie _a_u_t_o_m_o_u_n_t would have to mount the filesystem twice. _C_o_m_m_e_n_t_s _a_n_d _Q_u_o_t_i_n_g A mapping can be continued across input lines by escaping the NEWLINE with a backslash. Comments begin with a # and end at the subsequent NEWLINE. Characters that have special significance to the automount map parser may be protected either with double quotes (") or by escaping with a backslash (\). Pathnames with embedded whitespace, colons (:) or dollars ($) should be protected. _D_i_r_e_c_t_o_r_y _P_a_t_t_e_r_n _M_a_t_c_h_i_n_g The `&' character is expanded to the value of the _d_i_r_e_c_t_o_r_y field for the entry in which it occurs. In this case: bart springfield:/home/simpsons:& the & expands to _b_a_r_t. The `*' character, when supplied as the _d_i_r_e_c_t_o_r_y field, is recognized as the catch-all entry. Such an entry will be used if any previous entry has not successfully matched the key being searched for. For instance, if the following entry appeared in the indirect map for /_h_o_m_e: * &:/home/& this would allow automatic mounts in /_h_o_m_e of any remote filesystem whose location could be specified as: _h_o_s_t_n_a_m_e:/_h_o_m_e/_h_o_s_t_n_a_m_e _M_u_l_t_i_p_l_e _M_o_u_n_t_s A multiple mount entry takes the form: _d_i_r_e_c_t_o_r_y [ /[ _s_u_b_d_i_r_e_c_t_o_r_y [ ----_m_o_u_n_t-_o_p_t_i_o_n_s ] _l_o_c_a_t_i_o_n ... ] ... The initial / preceding the _s_u_b_d_i_r_e_c_t_o_r_y is required; the optional _s_u_b_d_i_r_e_c_t_o_r_y is taken as a pathname relative to the _d_i_r_e_c_t_o_r_y. If _s_u_b_d_i_r_e_c_t_o_r_y is omitted in the first occurrence, the / refers to the directory itself. PPPPaaaaggggeeee 5555 AAAAUUUUTTTTOOOOMMMMOOOOUUUUNNNNTTTT((((1111MMMM)))) AAAAUUUUTTTTOOOOMMMMOOOOUUUUNNNNTTTT((((1111MMMM)))) Given the direct map entry: /tools \ / -ro dill:/tools mint:/tools \ /1.0 -ro mint:/tools/1.0 dill:/tools/1.0 \ /1.0/man -ro dill:/tools/1.0/man mint:/tools/1.0/man _a_u_t_o_m_o_u_n_t would automatically mount /_t_o_o_l_s, /_t_o_o_l_s/_1._0 and /_t_o_o_l_s/_1._0/_m_a_n, as needed, from either _d_i_l_l or _m_i_n_t, whichever host responded first. If the mounts are hierarchically related, mounts closer to the root must appear before submounts. All the mounts of a multiple mount entry will occur together and will be unmounted together. This is important if the filesystems reference each other with relative symbolic links. Multiple mount entries can be used both in direct maps and in indirect maps. IIIInnnncccclllluuuuddddeeeedddd MMMMaaaappppssss The contents of another map can be included within a map with an entry of the form: +_m_a_p_n_a_m_e _m_a_p_n_a_m_e can either be a filename, or the name of an NIS map, or one of the special maps described below. If the directory being searched for is not located in an included map, the search continues with the next entry. SSSSppppeeeecccciiiiaaaallll MMMMaaaappppssss There are two special maps currently available: -_h_o_s_t_s and -_n_u_l_l. The -_h_o_s_t_s map uses the NIS _h_o_s_t_s._b_y_n_a_m_e map to locate a remote host when the hostname is specified. This map specifies mounts of all exported filesystems from any host. For instance, if the following _a_u_t_o_m_o_u_n_t command is already in effect: automount /hosts -hosts then a reference to /_h_o_s_t_s/_s_p_r_i_n_g_f_i_e_l_d/_u_s_r would initiate an automatic mount of all filesystems from _s_p_r_i_n_g_f_i_e_l_d that _a_u_t_o_m_o_u_n_t can mount; references to a directory under /_h_o_s_t_s/_s_p_r_i_n_g_f_i_e_l_d will refer to the corresponding directory relative to _s_p_r_i_n_g_f_i_e_l_d's root. The -_n_u_l_l map, when indicated on the command line, cancels any subsequent map for the directory indicated. It can be used to cancel a map given in _a_u_t_o._m_a_s_t_e_r or for a mount point specified as an entry in a direct map. CCCCoooonnnnffffiiiigggguuuurrrraaaattttiiiioooonnnn aaaannnndddd tttthhhheeee aaaauuuuttttoooo....mmmmaaaasssstttteeeerrrr MMMMaaaapppp _a_u_t_o_m_o_u_n_t normally consults the _a_u_t_o._m_a_s_t_e_r NIS configuration map for a list of initial automount maps, and sets up automatic mounts for them in addition to those given on the command line. If there are duplications, the command-line arguments take precedence over a local ----ffff master map and they both take precedence over an NIS _a_u_t_o._m_a_s_t_e_r map. This configuration database contains arguments to the automount command, rather than mappings; unless ----ffff is in effect, _a_u_t_o_m_o_u_n_t does _n_o_t look for PPPPaaaaggggeeee 6666 AAAAUUUUTTTTOOOOMMMMOOOOUUUUNNNNTTTT((((1111MMMM)))) AAAAUUUUTTTTOOOOMMMMOOOOUUUUNNNNTTTT((((1111MMMM)))) an _a_u_t_o._m_a_s_t_e_r file on the local host. Maps given on the command line, or those given in a local _a_u_t_o._m_a_s_t_e_r file specified with ----ffff override those in the NIS _a_u_t_o._m_a_s_t_e_r map. For instance, given the command: automount -f /etc/auto.master /home -null /- /etc/auto.direct and a file named /_e_t_c/_a_u_t_o._m_a_s_t_e_r that contains: /homes auto.home _a_u_t_o_m_o_u_n_t would mount home directories under /_h_o_m_e_s instead of /_h_o_m_e, in addition to the various directories specified in the /_e_t_c/_a_u_t_o._d_i_r_e_c_t file. FFFFIIIILLLLEEEESSSS /tmp_mnt directory under which filesystems are dynamically mounted /etc/config/automount.options site-dependent options and arguments SSSSEEEEEEEE AAAALLLLSSSSOOOO mount(1M), network(1M), chkconfig(1M), fstab(4), exports(4), schedctl(2) NNNNOOOOTTTTEEEESSSS The -_h_o_s_t_s map mounts all of the exported filesystems, for which the client has access, from a server. Use of the _n_o_h_i_d_e export option on the server (see exports(4)) may be used to minimize the number of mounts performed by clients. Automount will not request a separate mount for a _n_o_h_i_d_e filesystem, if the client has access via the parent filesystem. If frequent access to just a single filesystem is required, it is more efficient to access the filesystem with a map entry that is tailored to mount just the filesystem of interest. When it receives signal number 1, SIGHUP, _a_u_t_o_m_o_u_n_t rereads the /_e_t_c/_m_t_a_b file to update its internal record of currently-mounted filesystems. If a filesystem mounted with _a_u_t_o_m_o_u_n_t is unmounted with the _u_m_o_u_n_t(1M) command, _a_u_t_o_m_o_u_n_t should be forced to reread the file by using the command /etc/killall -HUP automount An _l_s(1) listing of the entries in the directory for an indirect map shows only the symbolic links for currently mounted filesystems. This restriction is intended to avoid unnecessary mounts as a side effect of programs that read the directory and _s_t_a_t(2) each of the names. Mount points for a single automounter must not be hierarchically related. _a_u_t_o_m_o_u_n_t will not allow an automount mount point to be created within an automounted filesystem. PPPPaaaaggggeeee 7777 AAAAUUUUTTTTOOOOMMMMOOOOUUUUNNNNTTTT((((1111MMMM)))) AAAAUUUUTTTTOOOOMMMMOOOOUUUUNNNNTTTT((((1111MMMM)))) The recommended way to terminate automount services is to send a SIGTERM signal to the daemon: /etc/killall -TERM automount This allows the automounter to catch the signal and unmount not only its daemon but also any mounts in /_t_m_p__m_n_t. Mounts in /_t_m_p__m_n_t that are busy will not be unmounted. _a_u_t_o_m_o_u_n_t must not be terminated with the SIGKILL signal. Without an opportunity to unmount itself, the automount mount points will appear to the kernel to belong to a non-responding NFS server. Since each direct map entry results in a separate mount for the mount daemon, such maps should be kept short. Although both direct and indirect maps can be modified at any time, entries added to a direct map will have no effect until the automounter is restarted. Automount mount points are mounted with type _i_g_n_o_r_e; they do not appear in the output of either _m_o_u_n_t(1M) or _d_f(1). Automatically-mounted filesystems, on the other hand, are mounted with type _n_f_s and are reported along with other NFS-mounted filesystems. BBBBUUUUGGGGSSSS Shell filename expansion does not apply to objects not currently mounted. The _b_g mount option is not recognized by the automounter. Since _a_u_t_o_m_o_u_n_t is single-threaded, any request that is delayed by a slow or non-responding NFS server will delay all subsequent automatic mount requests until it completes. Programs that read /_e_t_c/_m_t_a_b and then touch files that reside under automatic mount points will introduce further entries to the file. PPPPaaaaggggeeee 8888