Manual Pages for UNIX Operating System command usage for man mount_cachefs

System Administration Commands                  mount_cachefs(1M)



NAME
     mount_cachefs - mount CacheFS file systems

SYNOPSIS
     mount -F cachefs [generic_options] -o backfstype=file_system_type
          [specific_options]
          [-O] special mount_point


DESCRIPTION
     The CacheFS-specific version of the mount command  mounts  a
     cached  file  system;  if  necessary, it NFS-mounts its back
     file system. It also provides a number  of  CacheFS-specific
     options for controlling the caching process. For more infor-
     mation regarding back file systems, refer to the .


     mount_cachefs cannot be used  with  replicated  NFS  mounts.
     mount_cachefs  creates  a pass through when used with an NFS
     version 4 mount. No caching is performed.

OPTIONS
     To mount a CacheFS file system, use the generic  mount  com-
     mand with the -F option followed by the argument cachefs.


     See mount(1M) for a list of supported generic_options.

     -o specific_options    Specify CacheFS file system  specific
                            options  in  a  comma-separated  list
                            with no intervening spaces.

                            acdirmax=n

                                Specifies that cached  attributes
                                are  held  for  no  more  than  n
                                seconds after  directory  update.
                                After  n  seconds,  all directory
                                information is  purged  from  the
                                cache.  The  default  value is 30
                                seconds.


                            acdirmin=n

                                Specifies that cached  attributes
                                are  held  for at least n seconds
                                after directory update.  After  n
                                seconds, CacheFS checks to see if
                                the directory  modification  time
                                on   the  back  file  system  has
                                changed.   If   it    has,    all



SunOS 5.11          Last change: 18 Mar 2004                    1






System Administration Commands                  mount_cachefs(1M)



                                information  about  the directory
                                is purged from the cache and  new
                                data  is  retrieved from the back
                                file system. The default value is
                                30 seconds.


                            acregmax=n

                                Specifies that cached  attributes
                                are  held  for  no  more  than  n
                                seconds after file  modification.
                                After  n seconds, all file infor-
                                mation is purged from the  cache.
                                The default value is 30 seconds.


                            acregmin=n

                                Specifies that cached  attributes
                                are  held  for at least n seconds
                                after file modification. After  n
                                seconds, CacheFS checks to see if
                                the file modification time on the
                                back  file system has changed. If
                                it has, all information about the
                                file is purged from the cache and
                                new data is  retrieved  from  the
                                back  file  system.  The  default
                                value is 30 seconds.


                            actimeo=n

                                Sets acregmin,  acregmax,  acdir-
                                min, and acdirmax to n.


                            backfstype=file_system_type

                                The file system type of the  back
                                file system (can be nfs or hsfs).


                            backpath=path

                                Specifies  where  the  back  file
                                system  is  already  mounted.  If
                                this argument  is  not  supplied,
                                CacheFS  determines a mount point
                                for the  back  file  system.  The
                                back  file  system  must be read-



SunOS 5.11          Last change: 18 Mar 2004                    2






System Administration Commands                  mount_cachefs(1M)



                                only.


                            cachedir=directory

                                The name of the cache directory.


                            cacheid=ID

                                ID is a string specifying a  par-
                                ticular  instance  of a cache. If
                                you do not specify  a  cache  ID,
                                CacheFS will construct one.


                            demandconst

                                Verifies cache  consistency  only
                                when explicitly requested, rather
                                than the periodic  checking  that
                                is done by default. A consistency
                                check is requested by  using  the
                                -s  option  of  the  cfsadmin(1M)
                                command. This  option  is  useful
                                for back file systems that change
                                infrequently,    for     example,
                                /usr/openwin.   demandconst   and
                                noconst are mutually exclusive.


                            local-access

                                Causes the front file  system  to
                                interpret  the mode bits used for
                                access checking instead of having
                                the   back   file  system  verify
                                access permissions.  Do  not  use
                                this argument with secure NFS.


                            noconst

                                Disables cache consistency check-
                                ing.  By  default,  periodic con-
                                sistency  checking  is   enabled.
                                Specify  noconst  only  when  you
                                know that the  back  file  system
                                will  not  be modified. Trying to
                                perform cache  consistency  check
                                using  cfsadmin -s will result in
                                error.  demandconst  and  noconst



SunOS 5.11          Last change: 18 Mar 2004                    3






System Administration Commands                  mount_cachefs(1M)



                                are mutually exclusive.


                            write-around | non-shared

                                Write  modes  for  CacheFS.   The
                                write-around  mode  (the default)
                                handles writes the  same  as  NFS
                                does; that is, writes are made to
                                the back  file  system,  and  the
                                affected  file is purged from the
                                cache. You can use the non-shared
                                mode  when  you  are sure that no
                                one else will be writing  to  the
                                cached file system. In this mode,
                                all writes are made to  both  the
                                front  and  the back file system,
                                and  the  file  remains  in   the
                                cache.



     -O                     Overlay mount. Allows the  filesystem
                            to  be mounted over an existing mount
                            point, making the underlying filesys-
                            tem   inaccessible.  If  a  mount  is
                            attempted  on  a  pre-existing  mount
                            point   without  setting  this  flag,
                            mount will fail with the error: mount
                            -F cachefs: mount failed Device busy.


EXAMPLES
     Example 1 CacheFS-mounting a File System


     The  following  example  CacheFS-mounts  the   file   system
     server1:/user2,  which is already NFS-mounted on /usr/abc as
     /xyz.


       example# mount -F cachefs -o backfstype=nfs,backpath=/usr/abc,
            cachedir=/cache1 server1:/user2 /xyz




     The lines similar to the following appear in the /etc/mnttab
     file after the mount command is executed:


       server1:/user2   /usr/abc        nfs



SunOS 5.11          Last change: 18 Mar 2004                    4






System Administration Commands                  mount_cachefs(1M)



       /usr/abc         /cache1/xyz    cachefs     backfstype=nfs



ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:



     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Availability                | SUNWcs                      |
    |_____________________________|_____________________________|


SEE ALSO
     cfsadmin(1M), fsck_cachefs(1M), mount(1M), attributes(5)

BUGS
     The output for the generic_option -p output is incorrect for
     cachefs.
































SunOS 5.11          Last change: 18 Mar 2004                    5