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SunOS man pages : mount_cachefs (1)

Maintenance 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 System Administration Guide, Volume 1.

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 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 information 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 SunOS 5.8 Last change: 6 Apr 1998 1 Maintenance Commands mount_cachefs(1M) 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, acdirmin, 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- only. cachedir=directory The name of the cache directory. cacheid=ID ID is a string specifying a particular 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 mutu- ally 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 per- missions. Do not use this argument with secure NFS. noconst Disables cache consistency checking. By default, periodic consistency checking is enabled. Specify noconst only when you know that the back SunOS 5.8 Last change: 6 Apr 1998 2 Maintenance Commands mount_cachefs(1M) file system will not be modified. Trying to per- form cache consistency check using cfsadmin -s will result in error. demandconst and noconst are mutually exclusive. purge Purge any cached information for the specified file system. ro | rw Read-only or read-write (default). suid | nosuid Allow (default) or disallow setuid execution. 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 filesystem 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 /usr/abc /cache1/xyz cachefs backfstype=nfs

ATTRIBUTES

See attributes(5) for descriptions of the following attri- butes: SunOS 5.8 Last change: 6 Apr 1998 3 Maintenance Commands mount_cachefs(1M) ____________________________________________________________ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | |_____________________________|_____________________________| | Availability | SUNWcsu | |_____________________________|_____________________________|

SEE ALSO

cfsadmin(1M), fsck_cachefs(1M), mount(1M), attributes(5) System Administration Guide, Volume 1 SunOS 5.8 Last change: 6 Apr 1998 4