xref: /dflybsd-src/bin/cpdup/cpdup.1 (revision efda3bd00c039d6845508b47bb18d1687c72154e)
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.
4.\"
5.\"
6.\" $DragonFly: src/bin/cpdup/cpdup.1,v 1.15 2006/08/18 01:42:58 swildner Exp $
7.Dd October 28, 1999
8.Dt CPDUP 1
9.Os BSD 4
10.Sh NAME
11.Nm cpdup
12.Nd mirror filesystems
13.Sh SYNOPSIS
14.Nm cpdup
15.Op Fl v[vv..]
16.Op Fl u
17.Op Fl I
18.Op Fl f
19.Op Fl s0
20.Op Fl i0
21.Op Fl q
22.Op Fl o
23.Op Fl m
24.Oo
25.Fl H
26.Ar path
27.Oc
28.Oo
29.Fl M
30.Ar file
31.Oc
32.Op Fl S
33.Op Fl k
34.Oo
35.Fl K
36.Ar file
37.Oc
38.Oo
39.Fl X
40.Ar file
41.Oc
42.Op Fl x
43.Ar [[user@]host:]source_dir
44.Ar [[user@]host:]target_dir
45.Sh DESCRIPTION
46The
47.Nm
48utility makes an exact mirror copy of the source in the destination, creating
49and deleting files and directories as necessary.  UTimes, hardlinks,
50softlinks, devices, permissions, and flags are mirrored.  By default,
51.Nm
52asks for confirmation if any file or directory needs to be removed from
53the destination and does not copy files which it believes to have already
54been synchronized (by observing that the source and destination file's size
55and mtimes match).
56.Nm
57does not cross mount points in either the source or the destination.
58As a safety measure,
59.Nm
60refuses to replace a destination directory with a file.
61.Pp
62The following options are available:
63.Bl -tag -width flag
64.It Fl v[vv]
65Set verboseness.  By default
66.Nm
67does not report its progress except when asking for confirmation.  A single
68.Fl v
69will only report modifications made to the destination.
70.Fl vv
71will report directories as they are being traversed as well as
72modifications made to the destination.
73.Fl vvv
74will cause all files and directories to be reported whether or not
75modifications are made.
76.It Fl u
77Causes the ouptut generated by
78.Fl v[vv]
79to be unbuffered.
80This can be useful for obtaining prompt progress updates through a pipe.
81.It Fl I
82will cause cpdup to print a summary at the end with performance counter.
83.It Fl f
84Forces file updates to occur even if the files appear to be the same.  If
85the
86.Fl H
87option is used, this option will also force a byte for byte comparison
88between the original file and the file in the hardlink path, even if
89all the stat info matches, but will still use a hardlink if they match.
90.It Fl s0
91Disable the disallow-file-replaces-directory safety feature.  This
92safety feature is enabled by default to prevent user mistakes from blowing
93away everything accidently.
94.It Fl i0
95Do not request confirmation when removing something.
96.It Fl q
97Quiet operation
98.It Fl o
99Do not remove any files, just overwrite/add.
100.It Fl m
101Generate and maintain a MD5 checkfile in each directory on the source
102and do an MD5 check on each file of the destination when the destination
103appears to be the same as the source.  If the check fails,
104.Nm
105the source is recopied to the destination.  When you specify a destination
106directory the MD5 checkfile is only updated as needed and may not be updated
107even if modifications are made to a source file.  If you do not specify a
108destination directory the
109.Nm
110command forcefully regenerates the MD5 checkfile for every file in the source.
111.It Fl H Ar path
112cpdup will create a hardlink from a file found under
113.Ar path
114to the target instead of copying the source to the target if the file found
115via
116.Ar path
117is identical to the source.
118Note that a remote host specification should not be used in this option,
119but the path will be relative to the target machine.
120.Pp
121This allows one to use
122.Nm
123to create incremental backups of a filesystem.  Create a direct 'level 0'
124backup, and then specify the level 0 backup path with this option when
125creating an incremental backup to a different target directory.
126This method works so long as the filesystem does not hit a hardlink limit.
127If the system does hit a hardlink limit
128.Nm
129will generate a warning and copy the file instead.
130Note that
131.Nm
132must record file paths for any hardlinked file while operating and therefore
133uses a great deal more memory when dealing with hardlinks or hardlink-based
134backups.  Example use:
135.Pp
136.Dl cpdup -i0 -s0 -I -H /backup/home.l0 /home /backup/home.l1
137.Pp
138WARNING: If this option is used
139.Nm
140must record the paths for all files it encounters while it operates
141and it is possible that you may run the process out of memory.
142.It Fl M Ar file
143Works the same as
144.Fl m
145but allows you to specify the name of the MD5 checkfile.
146.It Fl S
147This places
148.Nm
149into slave mode and is used to initiate the slave protocol on a remote
150machine.
151.It Fl k
152Generate and maintain a FSMID checkfile called .FSMID.CHECK in each
153directory on the target.
154.Nm
155will check the FSMID for each source file or directory against the checkfile
156on the target and will not copy the file or recurse through the directory
157when a match occurs.  Any source file or directory with the same name as the
158checkfile will be ignored.  The FSMID will be re-checked after the copy
159has been completed and
160.Nm
161will loop on that directory or file until it is sure it has an exact copy.
162.Pp
163Warning: FSMID is not always supported by a filesystem and may not be
164synchronized if a crash occurs.  DragonFly will simulate an FSMID when
165it is otherwise not supported by the filesystem, and users should be aware
166that simulated FSMIDs may change state in such cases even if the underlying
167hierarchy does not due to cache flushes.
168Additionally, the FSMID may not reflect changes made to remote filesystems
169by other hosts.  For example, using these options with NFS mounted sources
170will not work well.
171.It Fl K Ar file
172Works the same as
173.Fl k
174but allows you to specify the name of the FSMID checkfile.
175.It Fl x
176Causes
177.Nm
178to use the exclusion file ".cpignore" in each directory on the source to
179determine which files to ignore.  When this option is used, the exclusion
180filename itself is automatically excluded from the copy.  If this option is
181not used then the filename ".cpignore" is not considered special and will
182be copied along with everything else.
183.It Fl X Ar file
184Works the same as
185.Fl x
186but allows you to specify the name of the exclusion file.  This file is
187automatically excluded from the copy.  Only one exclusion file may be
188specified.
189.El
190.Sh REMOTE COPYING
191.Nm
192can mirror directory structures across machines and can also do third-party
193copies.
194.Xr ssh 1
195sessions are used and
196.Nm
197is run on the remote machine(s) in slave mode.
198.Sh DIAGNOSTICS
199The
200.Nm
201utility exits 0 if no error occured and >0 if an error occured.
202.Sh SEE ALSO
203.Xr cp 1 ,
204.Xr cpio 1 ,
205.Xr tar 1
206.Sh HISTORY
207The
208.Nm
209command was original created to update servers at BEST Internet circa 1997
210and was placed under the FreeBSD copyright for inclusion in the ports area
211in 1999.  The program was written by Matthew Dillon and Dima Ruban.
212.Sh BUGS
213UFS has a hardlink limit of 32767.  Many programs, in particular CVS
214with regards to its CVS/Root file, will generate a lot of hard links.
215When using the
216.Fl H
217option it may not be possible for
218.Nm
219to maintain these hard links.  If this occurs
220.Nm
221will be forced to copy the file instead of link it, and thus not be able
222to make a perfect copy of the filesystem.
223