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 1.21 2007/02/24 13:00:32 swildner Exp $
12 .Nd mirror filesystems
44 .Ar [[user@]host:]source_dir
45 .Ar [[user@]host:]target_dir
49 utility makes an exact mirror copy of the source in the destination, creating
50 and deleting files and directories as necessary. UTimes, hardlinks,
51 softlinks, devices, permissions, and flags are mirrored. By default,
53 asks for confirmation if any file or directory needs to be removed from
54 the destination and does not copy files which it believes to have already
55 been synchronized (by observing that the source and destination file's size
58 does not cross mount points in either the source or the destination.
61 refuses to replace a destination directory with a file.
63 The following options are available:
66 Set verboseness. By default
68 does not report its progress except when asking for confirmation. A single
70 will only report modifications made to the destination.
72 will report directories as they are being traversed as well as
73 modifications made to the destination.
75 will cause all files and directories to be reported whether or not
76 modifications are made.
78 Causes the ouptut generated by
81 This can be useful for obtaining prompt progress updates through a pipe.
83 will cause cpdup to print a summary at the end with performance counter.
85 Forces file updates to occur even if the files appear to be the same. If
88 option is used, this option will force a byte for byte comparison
89 between the original file and the file in the hardlink path, even if
90 all the stat info matches, but will still use a hardlink if they match.
92 Disable the disallow-file-replaces-directory safety feature. This
93 safety feature is enabled by default to prevent user mistakes from blowing
94 away everything accidently.
96 Do not request confirmation when removing something.
98 Do not try to recreate CHR or BLK devices.
102 Do not remove any files, just overwrite/add.
104 Generate and maintain a MD5 checkfile in each directory on the source
105 and do an MD5 check on each file of the destination when the destination
106 appears to be the same as the source. If the check fails,
108 the source is recopied to the destination. When you specify a destination
109 directory the MD5 checkfile is only updated as needed and may not be updated
110 even if modifications are made to a source file. If you do not specify a
111 destination directory the
113 command forcefully regenerates the MD5 checkfile for every file in the source.
115 cpdup will create a hardlink from a file found under
117 to the target instead of copying the source to the target if the file found
120 is identical to the source.
121 Note that a remote host specification should not be used in this option,
122 but the path will be relative to the target machine.
124 This allows one to use
126 to create incremental backups of a filesystem. Create a direct 'level 0'
127 backup, and then specify the level 0 backup path with this option when
128 creating an incremental backup to a different target directory.
129 This method works so long as the filesystem does not hit a hardlink limit.
130 If the system does hit a hardlink limit
132 will generate a warning and copy the file instead.
135 must record file paths for any hardlinked file while operating and therefore
136 uses a great deal more memory when dealing with hardlinks or hardlink-based
137 backups. Example use:
139 .Dl cpdup -i0 -s0 -I -H /backup/home.l0 /home /backup/home.l1
141 WARNING: If this option is used
143 must record the paths for all files it encounters while it operates
144 and it is possible that you may run the process out of memory.
148 but allows you to specify the name of the MD5 checkfile.
152 into slave mode and is used to initiate the slave protocol on a remote
155 Generate and maintain a FSMID checkfile called .FSMID.CHECK in each
156 directory on the target.
158 will check the FSMID for each source file or directory against the checkfile
159 on the target and will not copy the file or recurse through the directory
160 when a match occurs. Any source file or directory with the same name as the
161 checkfile will be ignored. The FSMID will be re-checked after the copy
162 has been completed and
164 will loop on that directory or file until it is sure it has an exact copy.
166 Warning: FSMID is not always supported by a filesystem and may not be
167 synchronized if a crash occurs.
169 will simulate an FSMID when
170 it is otherwise not supported by the filesystem, and users should be aware
171 that simulated FSMIDs may change state in such cases even if the underlying
172 hierarchy does not due to cache flushes.
173 Additionally, the FSMID may not reflect changes made to remote filesystems
174 by other hosts. For example, using these options with NFS mounted sources
179 but allows you to specify the name of the FSMID checkfile.
183 to use the exclusion file ".cpignore" in each directory on the source to
184 determine which files to ignore. When this option is used, the exclusion
185 filename itself is automatically excluded from the copy. If this option is
186 not used then the filename ".cpignore" is not considered special and will
187 be copied along with everything else.
191 but allows you to specify the name of the exclusion file. This file is
192 automatically excluded from the copy. Only one exclusion file may be
197 can mirror directory structures across machines and can also do third-party
200 sessions are used and
202 is run on the remote machine(s) in slave mode.
206 utility exits 0 if no error occured and >0 if an error occured.
214 command was originally created to update servers at BEST Internet circa 1997
215 and was placed under the FreeBSD copyright for inclusion in the ports area
216 in 1999. The program was written by Matthew Dillon and Dima Ruban.
218 UFS has a hardlink limit of 32767. Many programs, in particular CVS
219 with regards to its CVS/Root file, will generate a lot of hard links.
222 option it may not be possible for
224 to maintain these hard links. If this occurs
226 will be forced to copy the file instead of link it, and thus not be able
227 to make a perfect copy of the filesystem.