1 .\" (c) Copyright 1997-2009 by Matthew Dillon and Dima Ruban. Permission to
2 .\" use and distribute based on the DragonFly copyright. Supplied as-is,
3 .\" USE WITH EXTREME CAUTION.
10 .Nd mirror filesystems
14 .Op Fl v Ns Op Cm v Ns Op Cm v
35 .Oo Oo Ar user Ns Li @ Oc Ns Ar host : Oc Ns Ar source_dir
36 .Oo Oo Ar user Ns Li @ Oc Ns Ar host : Oc Ns Ar target_dir
40 utility makes an exact mirror copy of the source in the destination, creating
41 and deleting files and directories as necessary. UTimes, hardlinks,
42 softlinks, devices, permissions, and flags are mirrored. By default,
44 asks for confirmation if any file or directory needs to be removed from
45 the destination and does not copy files which it believes to have already
46 been synchronized (by observing that the source and destination files' sizes
49 does not cross mount points in either the source or the destination.
52 refuses to replace a destination directory with a file.
54 The following options are available:
57 If the source or target is a remote host, request that the
59 session be compressed.
63 .It Fl v Ns Op Cm v Ns Op Cm v
64 Set verboseness. By default
66 does not report its progress except when asking for confirmation. A single
68 will only report modifications made to the destination.
70 will report directories as they are being traversed as well as
71 modifications made to the destination.
73 will cause all files and directories to be reported whether or not
74 modifications are made.
76 Print directories as they are being traversed.
77 Useful to watch the progress;
78 this typically produces much less output than
81 Causes the output generated by
86 This can be useful for obtaining prompt progress updates through a pipe.
90 to print a summary at the end with performance counters.
92 Forces file updates to occur even if the files appear to be the same. If
95 option is used, this option will force a byte for byte comparison
96 between the original file and the file in the hardlink path, even if
97 all the stat info matches, but will still use a hardlink if they match.
103 Note the lack of a space.
105 Disable the disallow-file-replaces-directory safety feature. This
106 safety feature is enabled by default to prevent user mistakes from blowing
107 away everything accidentally.
109 Do not request confirmation when removing something.
111 Do not try to recreate CHR or BLK devices.
113 Line buffer verbose output.
117 Do not remove any files, just overwrite/add.
119 Generate and maintain a MD5 checkfile called
121 in each directory on the source
122 and do an MD5 check on each file of the destination when the destination
123 appears to be the same as the source. If the check fails,
124 the source is recopied to the destination. When you specify a destination
125 directory, the MD5 checkfile is only updated as needed and may not be updated
126 even if modifications are made to a source file. If you do not specify a
127 destination directory the
129 command forcefully regenerates the MD5 checkfile for every file in the source.
133 but allows you to specify the name of the MD5 checkfile.
136 will create a hardlink from a file found under
138 to the target instead of copying the source to the target if the file found
141 is identical to the source.
142 Note that a remote host specification should not be used for this option's
146 will be relative to the target machine.
148 This allows one to use
150 to create incremental backups of a filesystem. Create a direct
152 backup, and then specify the level 0 backup path with this option when
153 creating an incremental backup to a different target directory.
154 This method works so long as the filesystem does not hit a hardlink limit.
155 If the system does hit a hardlink limit,
157 will generate a warning and copy the file instead.
160 must record file paths for any hardlinked file while operating and therefore
161 uses a great deal more memory when dealing with hardlinks or hardlink-based
162 backups. Example use:
164 .Dl cpdup \-i0 \-s0 \-I \-H /backup/home.l0 /home /backup/home.l1
166 WARNING: If this option is used
168 must record the paths for all files it encounters while it operates
169 and it is possible that you may run the process out of memory.
171 The file found via the hardlink path will be byte-by-byte compared with the
176 option is also used, otherwise only the stat info is checked to determine
177 whether it matches the source.
179 This forces the contents of regular files to be verified, even if the
180 files appear to the be the same. Whereas the
182 (force) option forces a copy regardless, this option will avoid rewriting
183 the target if everything matches and the contents are verified to be the
188 into slave mode and is used to initiate the slave protocol on a remote
191 Generate and maintain a FSMID checkfile called
193 in each directory on the target.
195 will check the FSMID for each source file or directory against the checkfile
196 on the target and will not copy the file or recurse through the directory
197 when a match occurs. Any source file or directory with the same name as the
198 checkfile will be ignored. The FSMID will be re-checked after the copy
199 has been completed and
201 will loop on that directory or file until it is sure it has an exact copy.
203 Warning: FSMID is not always supported by a filesystem and may not be
204 synchronized if a crash occurs.
206 will simulate an FSMID when
207 it is otherwise not supported by the filesystem, and users should be aware
208 that simulated FSMIDs may change state in such cases even if the underlying
209 hierarchy does not due to cache flushes.
210 Additionally, the FSMID may not reflect changes made to remote filesystems
211 by other hosts. For example, using these options with NFS mounted sources
216 but allows you to specify the name of the FSMID checkfile.
220 to use the exclusion file
222 in each directory on the source to
223 determine which files to ignore. When this option is used, the exclusion
224 filename itself is automatically excluded from the copy. If this option is
225 not used then the filename
227 is not considered special and will
228 be copied along with everything else.
232 but allows you to specify the name of the exclusion file. This file is
233 automatically excluded from the copy. Only one exclusion file may be
238 can mirror directory structures across machines and can also do third-party
241 sessions are used and
243 is run on the remote machine(s) in slave mode.
246 option to pass additional flags to the ssh command if necessary.
248 The syntax of remote path specifications is similar to
250 In particular, that means that a local path containing a colon must
251 be preceded by a slash to prevent it being considered a remote host:
255 to look for a directory called
261 denotes the directory
263 on the local machine.
267 utility exits 0 if no error occurred and >0 if an error occurred.
277 command was originally created to update servers at BEST Internet circa 1997
278 and was placed under the
280 copyright for inclusion in the ports area in 1999.
281 The program was written by Matthew Dillon and Dima Ruban.
284 has a hardlink limit of 32767. Many programs, in particular CVS
285 with regards to its CVS/Root file, will generate a lot of hard links.
288 option it may not be possible for
290 to maintain these hard links. If this occurs,
292 will be forced to copy the file instead of link it, and thus not be able
293 to make a perfect copy of the filesystem.
295 Currently the remote protocol uses host byte order. Therefore,
297 cannot talk to machines that use a byte order
298 different from the local machine.
300 When so-called sparse files (i.e. files with "holes") are copied,
301 the holes will be filled in the target files, so they occupy
302 more physical disk space than the source files.
projects / dragonfly.git / blob