xref: /freebsd/sbin/restore/restore.8 (revision 2008043f386721d58158e37e0d7e50df8095942d)
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28.\"     @(#)restore.8	8.4 (Berkeley) 5/1/95
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30.Dd October 12, 2006
31.Dt RESTORE 8
32.Os
33.Sh NAME
34.Nm restore ,
35.Nm rrestore
36.Nd "restore files or file systems from backups made with dump"
37.Sh SYNOPSIS
38.Nm
39.Fl i
40.Op Fl dDhmNuvy
41.Op Fl b Ar blocksize
42.Op Fl f Ar file | Fl P Ar pipecommand
43.Op Fl s Ar fileno
44.Nm
45.Fl R
46.Op Fl dDNuvy
47.Op Fl b Ar blocksize
48.Op Fl f Ar file | Fl P Ar pipecommand
49.Op Fl s Ar fileno
50.Nm
51.Fl r
52.Op Fl dDNuvy
53.Op Fl b Ar blocksize
54.Op Fl f Ar file | Fl P Ar pipecommand
55.Op Fl s Ar fileno
56.Nm
57.Fl t
58.Op Fl dDhNuvy
59.Op Fl b Ar blocksize
60.Op Fl f Ar file | Fl P Ar pipecommand
61.Op Fl s Ar fileno
62.Op Ar
63.Nm
64.Fl x
65.Op Fl dDhmNuvy
66.Op Fl b Ar blocksize
67.Op Fl f Ar file | Fl P Ar pipecommand
68.Op Fl s Ar fileno
69.Op Ar
70.Sh DESCRIPTION
71The
72.Nm
73utility performs the inverse function of
74.Xr dump 8 .
75A full backup of a file system may be restored and
76subsequent incremental backups layered on top of it.
77Single files and
78directory subtrees may be restored from full or partial
79backups.
80The
81.Nm
82utility works across a network;
83to do this see the
84.Fl f
85and
86.Fl P
87flags described below.
88Other arguments to the command are file or directory
89names specifying the files that are to be restored.
90Unless the
91.Fl h
92flag is specified (see below),
93the appearance of a directory name refers to
94the files and (recursively) subdirectories of that directory.
95.Pp
96.Nm
97may also be invoked as
98.Nm rrestore .
99The
100.Bx 4.3
101option syntax is implemented for backward compatibility, but
102is not documented here.
103.Pp
104Exactly one of the following flags is required:
105.Bl -tag -width Ds
106.It Fl i
107This mode allows interactive restoration of files from a dump.
108After reading in the directory information from the dump,
109.Nm
110provides a shell like interface that allows the user to move
111around the directory tree selecting files to be extracted.
112The available commands are given below;
113for those commands that require an argument,
114the default is the current directory.
115.Bl -tag -width Fl
116.It Ic add Op Ar arg
117The current directory or specified argument is added to the list of
118files to be extracted.
119If a directory is specified, then it and all its descendents are
120added to the extraction list
121(unless the
122.Fl h
123flag is specified on the command line).
124Files that are on the extraction list are prepended with a ``*''
125when they are listed by
126.Ic ls .
127.It Ic \&cd Ar arg
128Change the current working directory to the specified argument.
129.It Ic delete Op Ar arg
130The current directory or specified argument is deleted from the list of
131files to be extracted.
132If a directory is specified, then it and all its descendents are
133deleted from the extraction list
134(unless the
135.Fl h
136flag is specified on the command line).
137The most expedient way to extract most of the files from a directory
138is to add the directory to the extraction list and then delete
139those files that are not needed.
140.It Ic extract
141All the files that are on the extraction list are extracted
142from the dump.
143The
144.Nm
145utility will ask which volume the user wishes to mount.
146The fastest way to extract a few files is to
147start with the last volume, and work towards the first volume.
148.It Ic help
149List a summary of the available commands.
150.It Ic \&ls Op Ar arg
151List the current or specified directory.
152Entries that are directories are appended with a ``/''.
153Entries that have been marked for extraction are prepended with a ``*''.
154If the verbose
155flag is set the inode number of each entry is also listed.
156.It Ic pwd
157Print the full pathname of the current working directory.
158.It Ic quit
159Exit immediately,
160even if the extraction list is not empty.
161.It Ic setmodes
162All the directories that have been added to the extraction list
163have their owner, modes, and times set;
164nothing is extracted from the dump.
165This is useful for cleaning up after a restore has been prematurely aborted.
166.It Ic verbose
167The sense of the
168.Fl v
169flag is toggled.
170When set, the verbose flag causes the
171.Ic ls
172command to list the inode numbers of all entries.
173It also causes
174.Nm
175to print out information about each file as it is extracted.
176.It Ic what
177Display dump header information, which includes: date,
178level, label, and the file system and host dump was made
179from.
180.El
181.It Fl R
182Request a particular tape of a multi volume set on which to restart
183a full restore
184(see the
185.Fl r
186flag below).
187This is useful if the restore has been interrupted.
188.It Fl r
189Restore (rebuild a file system).
190The target file system should be made pristine with
191.Xr newfs 8 ,
192mounted and the user
193.Xr cd 1 Ns 'd
194into the pristine file system
195before starting the restoration of the initial level 0 backup.
196If the
197level 0 restores successfully, the
198.Fl r
199flag may be used to restore
200any necessary incremental backups on top of the level 0.
201The
202.Fl r
203flag precludes an interactive file extraction and can be
204detrimental to one's health if not used carefully (not to mention
205the disk).
206An example:
207.Bd -literal -offset indent
208newfs /dev/da0s1a
209mount /dev/da0s1a /mnt
210cd /mnt
211
212restore rf /dev/sa0
213.Ed
214.Pp
215Note that
216.Nm
217leaves a file
218.Pa restoresymtable
219in the root directory to pass information between incremental
220restore passes.
221This file should be removed when the last incremental has been
222restored.
223.Pp
224The
225.Nm
226utility ,
227in conjunction with
228.Xr newfs 8
229and
230.Xr dump 8 ,
231may be used to modify file system parameters
232such as size or block size.
233.It Fl t
234The names of the specified files are listed if they occur
235on the backup.
236If no file argument is given,
237then the root directory is listed,
238which results in the entire content of the
239backup being listed,
240unless the
241.Fl h
242flag has been specified.
243Note that the
244.Fl t
245flag replaces the function of the old
246.Xr dumpdir 8
247program.
248.It Fl x
249The named files are read from the given media.
250If a named file matches a directory whose contents
251are on the backup
252and the
253.Fl h
254flag is not specified,
255the directory is recursively extracted.
256The owner, modification time,
257and mode are restored (if possible).
258If no file argument is given,
259then the root directory is extracted,
260which results in the entire content of the
261backup being extracted,
262unless the
263.Fl h
264flag has been specified.
265.El
266.Pp
267The following additional options may be specified:
268.Bl -tag -width Ds
269.It Fl b Ar blocksize
270The number of kilobytes per dump record.
271If the
272.Fl b
273option is not specified,
274.Nm
275tries to determine the media block size dynamically.
276.It Fl d
277Sends verbose debugging output to the standard error.
278.It Fl D
279This puts
280.Nm
281into degraded mode,
282causing restore to operate less efficiently
283but to try harder to read corrupted backups.
284.It Fl f Ar file
285Read the backup from
286.Ar file ;
287.Ar file
288may be a special device file
289like
290.Pa /dev/sa0
291(a tape drive),
292.Pa /dev/da1c
293(a disk drive),
294an ordinary file,
295or
296.Sq Fl
297(the standard input).
298If the name of the file is of the form
299.Dq host:file ,
300or
301.Dq user@host:file ,
302.Nm
303reads from the named file on the remote host using
304.Xr rmt 8 .
305.It Fl P Ar pipecommand
306Use
307.Xr popen 3
308to execute the
309.Xr sh 1
310script string defined by
311.Ar pipecommand
312as the input for every volume in the backup.
313This child pipeline's
314.Dv stdout
315.Pq Pa /dev/fd/1
316is redirected to the
317.Nm
318input stream, and the environment variable
319.Ev RESTORE_VOLUME
320is set to the current volume number being read.
321The
322.Ar pipecommand
323script is started each time a volume is loaded, as if it were a tape drive.
324.It Fl h
325Extract the actual directory,
326rather than the files that it references.
327This prevents hierarchical restoration of complete subtrees
328from the dump.
329.It Fl m
330Extract by inode numbers rather than by file name.
331This is useful if only a few files are being extracted,
332and one wants to avoid regenerating the complete pathname
333to the file.
334.It Fl N
335Do the extraction normally, but do not actually write any changes
336to disk.
337This can be used to check the integrity of dump media
338or other test purposes.
339.It Fl s Ar fileno
340Read from the specified
341.Ar fileno
342on a multi-file tape.
343File numbering starts at 1.
344.It Fl u
345When creating certain types of files, restore may generate a warning
346diagnostic if they already exist in the target directory.
347To prevent this, the
348.Fl u
349(unlink) flag causes restore to remove old entries before attempting
350to create new ones.
351This flag is recommended when using extended attributes
352to avoid improperly accumulating attributes on pre-existing files.
353.It Fl v
354Normally
355.Nm
356does its work silently.
357The
358.Fl v
359(verbose)
360flag causes it to type the name of each file it treats
361preceded by its file type.
362.It Fl y
363Do not ask the user whether to abort the restore in the event of an error.
364Always try to skip over the bad block(s) and continue.
365.El
366.Sh ENVIRONMENT
367.Bl -tag -width ".Ev TMPDIR"
368.It Ev TAPE
369Device from which to read backup.
370.It Ev TMPDIR
371Name of directory where temporary files are to be created.
372.El
373.Sh FILES
374.Bl -tag -width "./restoresymtable" -compact
375.It Pa /dev/sa0
376the default tape drive
377.It Pa /tmp/rstdir*
378file containing directories on the tape.
379.It Pa /tmp/rstmode*
380owner, mode, and time stamps for directories.
381.It Pa \&./restoresymtable
382information passed between incremental restores.
383.El
384.Sh DIAGNOSTICS
385The
386.Nm
387utility complains if it gets a read error.
388If
389.Fl y
390has been specified, or the user responds
391.Ql y ,
392.Nm
393will attempt to continue the restore.
394.Pp
395If a backup was made using more than one tape volume,
396.Nm
397will notify the user when it is time to mount the next volume.
398If the
399.Fl x
400or
401.Fl i
402flag has been specified,
403.Nm
404will also ask which volume the user wishes to mount.
405The fastest way to extract a few files is to
406start with the last volume, and work towards the first volume.
407.Pp
408There are numerous consistency checks that can be listed by
409.Nm .
410Most checks are self-explanatory or can ``never happen''.
411Common errors are given below.
412.Pp
413.Bl -tag -width Ds -compact
414.It <filename>: not found on tape
415The specified file name was listed in the tape directory,
416but was not found on the tape.
417This is caused by tape read errors while looking for the file,
418and from using a dump tape created on an active file system.
419.Pp
420.It expected next file <inumber>, got <inumber>
421A file that was not listed in the directory showed up.
422This can occur when using a dump created on an active file system.
423.Pp
424.It Incremental dump too low
425When doing incremental restore,
426a dump that was written before the previous incremental dump,
427or that has too low an incremental level has been loaded.
428.Pp
429.It Incremental dump too high
430When doing incremental restore,
431a dump that does not begin its coverage where the previous incremental
432dump left off,
433or that has too high an incremental level has been loaded.
434.Pp
435.It Tape read error while restoring <filename>
436.It Tape read error while skipping over inode <inumber>
437.It Tape read error while trying to resynchronize
438A tape (or other media) read error has occurred.
439If a file name is specified,
440then its contents are probably partially wrong.
441If an inode is being skipped or the tape is trying to resynchronize,
442then no extracted files have been corrupted,
443though files may not be found on the tape.
444.Pp
445.It resync restore, skipped <num> blocks
446After a dump read error,
447.Nm
448may have to resynchronize itself.
449This message lists the number of blocks that were skipped over.
450.El
451.Sh SEE ALSO
452.Xr dump 8 ,
453.Xr mount 8 ,
454.Xr newfs 8 ,
455.Xr rmt 8
456.Sh HISTORY
457The
458.Nm
459utility appeared in
460.Bx 4.2 .
461.Sh BUGS
462The
463.Nm
464utility can get confused when doing incremental restores from
465dumps that were made on active file systems without the
466.Fl L
467option (see
468.Xr dump 8 ) .
469.Pp
470A level zero dump must be done after a full restore.
471Because restore runs in user code,
472it has no control over inode allocation;
473thus a full dump must be done to get a new set of directories
474reflecting the new inode numbering,
475even though the contents of the files is unchanged.
476.Pp
477To do a network restore, you have to run restore as root.
478This is due
479to the previous security history of dump and restore.
480(restore is
481written to be setuid root, but we are not certain all bugs are gone
482from the restore code - run setuid at your own risk.)
483.Pp
484The temporary files
485.Pa /tmp/rstdir*
486and
487.Pa /tmp/rstmode*
488are generated with a unique name based on the date of the dump
489and the process ID (see
490.Xr mktemp 3 ) ,
491except for when
492.Fl r
493or
494.Fl R
495is used.
496Because
497.Fl R
498allows you to restart a
499.Fl r
500operation that may have been interrupted, the temporary files should
501be the same across different processes.
502In all other cases, the files are unique because it is possible to
503have two different dumps started at the same time, and separate
504operations should not conflict with each other.
505