1mount_cachefs(1M)       System Administration Commands       mount_cachefs(1M)
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NAME

6       mount_cachefs - mount CacheFS file systems
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SYNOPSIS

9       mount -F cachefs [generic_options] -o backfstype=file_system_type
10            [specific_options]
11            [-O] special mount_point
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13

DESCRIPTION

15       The  CacheFS-specific version of the mount command mounts a cached file
16       system; if necessary, it NFS-mounts its back file system. It also  pro‐
17       vides  a number of CacheFS-specific options for controlling the caching
18       process. For more information regarding back file systems, refer to the
19       .
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22       mount_cachefs  cannot be used with replicated NFS mounts. mount_cachefs
23       creates a pass through when used  with  an  NFS  version  4  mount.  No
24       caching is performed.
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OPTIONS

27       To  mount a CacheFS file system, use the generic mount command with the
28       -F option followed by the argument cachefs.
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30
31       See mount(1M) for a list of supported generic_options.
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33       -o specific_options    Specify CacheFS file system specific options  in
34                              a  comma-separated list with no intervening spa‐
35                              ces.
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37                              acdirmax=n
38
39                                  Specifies that cached  attributes  are  held
40                                  for  no  more than n seconds after directory
41                                  update.  After  n  seconds,  all   directory
42                                  information  is  purged  from the cache. The
43                                  default value is 30 seconds.
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45
46                              acdirmin=n
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48                                  Specifies that cached  attributes  are  held
49                                  for  at  least  n  seconds  after  directory
50                                  update. After n seconds, CacheFS  checks  to
51                                  see  if  the  directory modification time on
52                                  the back file system has changed. If it has,
53                                  all   information  about  the  directory  is
54                                  purged  from  the  cache  and  new  data  is
55                                  retrieved  from  the  back  file system. The
56                                  default value is 30 seconds.
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58
59                              acregmax=n
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61                                  Specifies that cached  attributes  are  held
62                                  for  no more than n seconds after file modi‐
63                                  fication. After n seconds, all file informa‐
64                                  tion  is  purged from the cache. The default
65                                  value is 30 seconds.
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67
68                              acregmin=n
69
70                                  Specifies that cached  attributes  are  held
71                                  for  at least n seconds after file modifica‐
72                                  tion. After n seconds, CacheFS checks to see
73                                  if  the  file  modification time on the back
74                                  file system has  changed.  If  it  has,  all
75                                  information  about  the  file is purged from
76                                  the cache and new data is retrieved from the
77                                  back  file  system.  The default value is 30
78                                  seconds.
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81                              actimeo=n
82
83                                  Sets  acregmin,  acregmax,   acdirmin,   and
84                                  acdirmax to n.
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86
87                              backfstype=file_system_type
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89                                  The file system type of the back file system
90                                  (can be nfs or hsfs).
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92
93                              backpath=path
94
95                                  Specifies where  the  back  file  system  is
96                                  already  mounted.  If  this  argument is not
97                                  supplied, CacheFS determines a  mount  point
98                                  for the back file system. The back file sys‐
99                                  tem must be read-only.
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101
102                              cachedir=directory
103
104                                  The name of the cache directory.
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106
107                              cacheid=ID
108
109                                  ID  is  a  string  specifying  a  particular
110                                  instance of a cache. If you do not specify a
111                                  cache ID, CacheFS will construct one.
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114                              demandconst
115
116                                  Verifies cache consistency only when explic‐
117                                  itly  requested,  rather  than  the periodic
118                                  checking that is done by default. A  consis‐
119                                  tency  check  is  requested  by using the -s
120                                  option of  the  cfsadmin(1M)  command.  This
121                                  option  is useful for back file systems that
122                                  change infrequently, for example, /usr/open‐
123                                  win.  demandconst  and  noconst are mutually
124                                  exclusive.
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126
127                              local-access
128
129                                  Causes the front file  system  to  interpret
130                                  the  mode  bits  used  for  access  checking
131                                  instead of having the back file system  ver‐
132                                  ify  access  permissions.  Do  not  use this
133                                  argument with secure NFS.
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135
136                              noconst
137
138                                  Disables  cache  consistency  checking.   By
139                                  default,  periodic  consistency  checking is
140                                  enabled. Specify noconst only when you  know
141                                  that  the back file system will not be modi‐
142                                  fied. Trying to  perform  cache  consistency
143                                  check  using  cfsadmin  -s  will  result  in
144                                  error. demandconst and noconst are  mutually
145                                  exclusive.
146
147
148                              write-around | non-shared
149
150                                  Write  modes  for  CacheFS. The write-around
151                                  mode (the default) handles writes  the  same
152                                  as NFS does; that is, writes are made to the
153                                  back file system, and the affected  file  is
154                                  purged  from the cache. You can use the non-
155                                  shared mode when you are sure  that  no  one
156                                  else will be writing to the cached file sys‐
157                                  tem. In this mode, all writes  are  made  to
158                                  both the front and the back file system, and
159                                  the file remains in the cache.
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162
163       -O                     Overlay  mount.  Allows  the  filesystem  to  be
164                              mounted over an existing mount point, making the
165                              underlying filesystem inaccessible. If  a  mount
166                              is attempted on a pre-existing mount point with‐
167                              out setting this flag, mount will fail with  the
168                              error:  mount  -F  cachefs:  mount failed Device
169                              busy.
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EXAMPLES

173       Example 1 CacheFS-mounting a File System
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175
176       The following example CacheFS-mounts the  file  system  server1:/user2,
177       which is already NFS-mounted on /usr/abc as /xyz.
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179
180         example# mount -F cachefs -o backfstype=nfs,backpath=/usr/abc,
181              cachedir=/cache1 server1:/user2 /xyz
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186       The lines similar to the following appear in the /etc/mnttab file after
187       the mount command is executed:
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189
190         server1:/user2   /usr/abc        nfs
191         /usr/abc         /cache1/xyz    cachefs     backfstype=nfs
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ATTRIBUTES

196       See attributes(5) for descriptions of the following attributes:
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201       ┌─────────────────────────────┬─────────────────────────────┐
202       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
203       ├─────────────────────────────┼─────────────────────────────┤
204       │Availability                 │SUNWcsu                      │
205       └─────────────────────────────┴─────────────────────────────┘
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SEE ALSO

208       cfsadmin(1M), fsck_cachefs(1M), mount(1M), attributes(5)
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BUGS

211       The output for the generic_option -p output is incorrect for cachefs.
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215SunOS 5.11                        18 Mar 2004                mount_cachefs(1M)
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