1 .\" (c) Copyright 1997-1999 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.
6 .\" $DragonFly: src/bin/cpdup/cpdup.1,v 1.17 2006/09/16 16:47:29 dillon Exp $
12 .Nd mirror filesystems
43 .Ar [[user@]host:]source_dir
44 .Ar [[user@]host:]target_dir
48 utility makes an exact mirror copy of the source in the destination, creating
49 and deleting files and directories as necessary. UTimes, hardlinks,
50 softlinks, devices, permissions, and flags are mirrored. By default,
52 asks for confirmation if any file or directory needs to be removed from
53 the destination and does not copy files which it believes to have already
54 been synchronized (by observing that the source and destination file's size
57 does not cross mount points in either the source or the destination.
60 refuses to replace a destination directory with a file.
62 The following options are available:
65 Set verboseness. By default
67 does not report its progress except when asking for confirmation. A single
69 will only report modifications made to the destination.
71 will report directories as they are being traversed as well as
72 modifications made to the destination.
74 will cause all files and directories to be reported whether or not
75 modifications are made.
77 Causes the ouptut generated by
80 This can be useful for obtaining prompt progress updates through a pipe.
82 will cause cpdup to print a summary at the end with performance counter.
84 Forces file updates to occur even if the files appear to be the same. If
87 option is used, this option will force a byte for byte comparison
88 between the original file and the file in the hardlink path, even if
89 all the stat info matches, but will still use a hardlink if they match.
91 Disable the disallow-file-replaces-directory safety feature. This
92 safety feature is enabled by default to prevent user mistakes from blowing
93 away everything accidently.
95 Do not request confirmation when removing something.
99 Do not remove any files, just overwrite/add.
101 Generate and maintain a MD5 checkfile in each directory on the source
102 and do an MD5 check on each file of the destination when the destination
103 appears to be the same as the source. If the check fails,
105 the source is recopied to the destination. When you specify a destination
106 directory the MD5 checkfile is only updated as needed and may not be updated
107 even if modifications are made to a source file. If you do not specify a
108 destination directory the
110 command forcefully regenerates the MD5 checkfile for every file in the source.
112 cpdup will create a hardlink from a file found under
114 to the target instead of copying the source to the target if the file found
117 is identical to the source.
118 Note that a remote host specification should not be used in this option,
119 but the path will be relative to the target machine.
121 This allows one to use
123 to create incremental backups of a filesystem. Create a direct 'level 0'
124 backup, and then specify the level 0 backup path with this option when
125 creating an incremental backup to a different target directory.
126 This method works so long as the filesystem does not hit a hardlink limit.
127 If the system does hit a hardlink limit
129 will generate a warning and copy the file instead.
132 must record file paths for any hardlinked file while operating and therefore
133 uses a great deal more memory when dealing with hardlinks or hardlink-based
134 backups. Example use:
136 .Dl cpdup -i0 -s0 -I -H /backup/home.l0 /home /backup/home.l1
138 WARNING: If this option is used
140 must record the paths for all files it encounters while it operates
141 and it is possible that you may run the process out of memory.
145 but allows you to specify the name of the MD5 checkfile.
149 into slave mode and is used to initiate the slave protocol on a remote
152 Generate and maintain a FSMID checkfile called .FSMID.CHECK in each
153 directory on the target.
155 will check the FSMID for each source file or directory against the checkfile
156 on the target and will not copy the file or recurse through the directory
157 when a match occurs. Any source file or directory with the same name as the
158 checkfile will be ignored. The FSMID will be re-checked after the copy
159 has been completed and
161 will loop on that directory or file until it is sure it has an exact copy.
163 Warning: FSMID is not always supported by a filesystem and may not be
164 synchronized if a crash occurs. DragonFly will simulate an FSMID when
165 it is otherwise not supported by the filesystem, and users should be aware
166 that simulated FSMIDs may change state in such cases even if the underlying
167 hierarchy does not due to cache flushes.
168 Additionally, the FSMID may not reflect changes made to remote filesystems
169 by other hosts. For example, using these options with NFS mounted sources
174 but allows you to specify the name of the FSMID checkfile.
178 to use the exclusion file ".cpignore" in each directory on the source to
179 determine which files to ignore. When this option is used, the exclusion
180 filename itself is automatically excluded from the copy. If this option is
181 not used then the filename ".cpignore" is not considered special and will
182 be copied along with everything else.
186 but allows you to specify the name of the exclusion file. This file is
187 automatically excluded from the copy. Only one exclusion file may be
192 can mirror directory structures across machines and can also do third-party
195 sessions are used and
197 is run on the remote machine(s) in slave mode.
201 utility exits 0 if no error occured and >0 if an error occured.
209 command was original created to update servers at BEST Internet circa 1997
210 and was placed under the FreeBSD copyright for inclusion in the ports area
211 in 1999. The program was written by Matthew Dillon and Dima Ruban.
213 UFS has a hardlink limit of 32767. Many programs, in particular CVS
214 with regards to its CVS/Root file, will generate a lot of hard links.
217 option it may not be possible for
219 to maintain these hard links. If this occurs
221 will be forced to copy the file instead of link it, and thus not be able
222 to make a perfect copy of the filesystem.