xref: /freebsd/sbin/restore/restore.8 (revision 7aa383846770374466b1dcb2cefd71bde9acf463)
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28.\"     @(#)restore.8	8.4 (Berkeley) 5/1/95
29.\" $FreeBSD$
30.\"
31.Dd October 12, 2006
32.Dt RESTORE 8
33.Os
34.Sh NAME
35.Nm restore ,
36.Nm rrestore
37.Nd "restore files or file systems from backups made with dump"
38.Sh SYNOPSIS
39.Nm
40.Fl i
41.Op Fl dDhmNuvy
42.Op Fl b Ar blocksize
43.Op Fl f Ar file | Fl P Ar pipecommand
44.Op Fl s Ar fileno
45.Nm
46.Fl R
47.Op Fl dDNuvy
48.Op Fl b Ar blocksize
49.Op Fl f Ar file | Fl P Ar pipecommand
50.Op Fl s Ar fileno
51.Nm
52.Fl r
53.Op Fl dDNuvy
54.Op Fl b Ar blocksize
55.Op Fl f Ar file | Fl P Ar pipecommand
56.Op Fl s Ar fileno
57.Nm
58.Fl t
59.Op Fl dDhNuvy
60.Op Fl b Ar blocksize
61.Op Fl f Ar file | Fl P Ar pipecommand
62.Op Fl s Ar fileno
63.Op Ar
64.Nm
65.Fl x
66.Op Fl dDhmNuvy
67.Op Fl b Ar blocksize
68.Op Fl f Ar file | Fl P Ar pipecommand
69.Op Fl s Ar fileno
70.Op Ar
71.Pp
72.Nm rrestore
73is an alternate name for
74.Nm .
75.Pp
76.in \" XXX
77(The
78.Bx 4.3
79option syntax is implemented for backward compatibility, but
80is not documented here.)
81.Sh DESCRIPTION
82The
83.Nm
84utility performs the inverse function of
85.Xr dump 8 .
86A full backup of a file system may be restored and
87subsequent incremental backups layered on top of it.
88Single files and
89directory subtrees may be restored from full or partial
90backups.
91The
92.Nm
93utility works across a network;
94to do this see the
95.Fl f
96and
97.Fl P
98flags described below.
99Other arguments to the command are file or directory
100names specifying the files that are to be restored.
101Unless the
102.Fl h
103flag is specified (see below),
104the appearance of a directory name refers to
105the files and (recursively) subdirectories of that directory.
106.Pp
107Exactly one of the following flags is required:
108.Bl -tag -width Ds
109.It Fl i
110This mode allows interactive restoration of files from a dump.
111After reading in the directory information from the dump,
112.Nm
113provides a shell like interface that allows the user to move
114around the directory tree selecting files to be extracted.
115The available commands are given below;
116for those commands that require an argument,
117the default is the current directory.
118.Bl -tag -width Fl
119.It Ic add Op Ar arg
120The current directory or specified argument is added to the list of
121files to be extracted.
122If a directory is specified, then it and all its descendents are
123added to the extraction list
124(unless the
125.Fl h
126flag is specified on the command line).
127Files that are on the extraction list are prepended with a ``*''
128when they are listed by
129.Ic ls .
130.It Ic \&cd Ar arg
131Change the current working directory to the specified argument.
132.It Ic delete Op Ar arg
133The current directory or specified argument is deleted from the list of
134files to be extracted.
135If a directory is specified, then it and all its descendents are
136deleted from the extraction list
137(unless the
138.Fl h
139flag is specified on the command line).
140The most expedient way to extract most of the files from a directory
141is to add the directory to the extraction list and then delete
142those files that are not needed.
143.It Ic extract
144All the files that are on the extraction list are extracted
145from the dump.
146The
147.Nm
148utility will ask which volume the user wishes to mount.
149The fastest way to extract a few files is to
150start with the last volume, and work towards the first volume.
151.It Ic help
152List a summary of the available commands.
153.It Ic \&ls Op Ar arg
154List the current or specified directory.
155Entries that are directories are appended with a ``/''.
156Entries that have been marked for extraction are prepended with a ``*''.
157If the verbose
158flag is set the inode number of each entry is also listed.
159.It Ic pwd
160Print the full pathname of the current working directory.
161.It Ic quit
162Exit immediately,
163even if the extraction list is not empty.
164.It Ic setmodes
165All the directories that have been added to the extraction list
166have their owner, modes, and times set;
167nothing is extracted from the dump.
168This is useful for cleaning up after a restore has been prematurely aborted.
169.It Ic verbose
170The sense of the
171.Fl v
172flag is toggled.
173When set, the verbose flag causes the
174.Ic ls
175command to list the inode numbers of all entries.
176It also causes
177.Nm
178to print out information about each file as it is extracted.
179.It Ic what
180Display dump header information, which includes: date,
181level, label, and the file system and host dump was made
182from.
183.El
184.It Fl R
185Request a particular tape of a multi volume set on which to restart
186a full restore
187(see the
188.Fl r
189flag below).
190This is useful if the restore has been interrupted.
191.It Fl r
192Restore (rebuild a file system).
193The target file system should be made pristine with
194.Xr newfs 8 ,
195mounted and the user
196.Xr cd 1 Ns 'd
197into the pristine file system
198before starting the restoration of the initial level 0 backup.
199If the
200level 0 restores successfully, the
201.Fl r
202flag may be used to restore
203any necessary incremental backups on top of the level 0.
204The
205.Fl r
206flag precludes an interactive file extraction and can be
207detrimental to one's health if not used carefully (not to mention
208the disk).
209An example:
210.Bd -literal -offset indent
211newfs /dev/da0s1a
212mount /dev/da0s1a /mnt
213cd /mnt
214
215restore rf /dev/sa0
216.Ed
217.Pp
218Note that
219.Nm
220leaves a file
221.Pa restoresymtable
222in the root directory to pass information between incremental
223restore passes.
224This file should be removed when the last incremental has been
225restored.
226.Pp
227The
228.Nm
229utility ,
230in conjunction with
231.Xr newfs 8
232and
233.Xr dump 8 ,
234may be used to modify file system parameters
235such as size or block size.
236.It Fl t
237The names of the specified files are listed if they occur
238on the backup.
239If no file argument is given,
240then the root directory is listed,
241which results in the entire content of the
242backup being listed,
243unless the
244.Fl h
245flag has been specified.
246Note that the
247.Fl t
248flag replaces the function of the old
249.Xr dumpdir 8
250program.
251.It Fl x
252The named files are read from the given media.
253If a named file matches a directory whose contents
254are on the backup
255and the
256.Fl h
257flag is not specified,
258the directory is recursively extracted.
259The owner, modification time,
260and mode are restored (if possible).
261If no file argument is given,
262then the root directory is extracted,
263which results in the entire content of the
264backup being extracted,
265unless the
266.Fl h
267flag has been specified.
268.El
269.Pp
270The following additional options may be specified:
271.Bl -tag -width Ds
272.It Fl b Ar blocksize
273The number of kilobytes per dump record.
274If the
275.Fl b
276option is not specified,
277.Nm
278tries to determine the media block size dynamically.
279.It Fl d
280Sends verbose debugging output to the standard error.
281.It Fl D
282This puts
283.Nm
284into degraded mode,
285causing restore to operate less efficiently
286but to try harder to read corrupted backups.
287.It Fl f Ar file
288Read the backup from
289.Ar file ;
290.Ar file
291may be a special device file
292like
293.Pa /dev/sa0
294(a tape drive),
295.Pa /dev/da1c
296(a disk drive),
297an ordinary file,
298or
299.Sq Fl
300(the standard input).
301If the name of the file is of the form
302.Dq host:file ,
303or
304.Dq user@host:file ,
305.Nm
306reads from the named file on the remote host using
307.Xr rmt 8 .
308.It Fl P Ar pipecommand
309Use
310.Xr popen 3
311to execute the
312.Xr sh 1
313script string defined by
314.Ar pipecommand
315as the input for every volume in the backup.
316This child pipeline's
317.Dv stdout
318.Pq Pa /dev/fd/1
319is redirected to the
320.Nm
321input stream, and the environment variable
322.Ev RESTORE_VOLUME
323is set to the current volume number being read.
324The
325.Ar pipecommand
326script is started each time a volume is loaded, as if it were a tape drive.
327.It Fl h
328Extract the actual directory,
329rather than the files that it references.
330This prevents hierarchical restoration of complete subtrees
331from the dump.
332.It Fl m
333Extract by inode numbers rather than by file name.
334This is useful if only a few files are being extracted,
335and one wants to avoid regenerating the complete pathname
336to the file.
337.It Fl N
338Do the extraction normally, but do not actually write any changes
339to disk.
340This can be used to check the integrity of dump media
341or other test purposes.
342.It Fl s Ar fileno
343Read from the specified
344.Ar fileno
345on a multi-file tape.
346File numbering starts at 1.
347.It Fl u
348When creating certain types of files, restore may generate a warning
349diagnostic if they already exist in the target directory.
350To prevent this, the
351.Fl u
352(unlink) flag causes restore to remove old entries before attempting
353to create new ones.
354.It Fl v
355Normally
356.Nm
357does its work silently.
358The
359.Fl v
360(verbose)
361flag causes it to type the name of each file it treats
362preceded by its file type.
363.It Fl y
364Do not ask the user whether to abort the restore in the event of an error.
365Always try to skip over the bad block(s) and continue.
366.El
367.Sh ENVIRONMENT
368.Bl -tag -width ".Ev TMPDIR"
369.It Ev TAPE
370Device from which to read backup.
371.It Ev TMPDIR
372Name of directory where temporary files are to be created.
373.El
374.Sh FILES
375.Bl -tag -width "./restoresymtable" -compact
376.It Pa /dev/sa0
377the default tape drive
378.It Pa /tmp/rstdir*
379file containing directories on the tape.
380.It Pa /tmp/rstmode*
381owner, mode, and time stamps for directories.
382.It Pa \&./restoresymtable
383information passed between incremental restores.
384.El
385.Sh DIAGNOSTICS
386The
387.Nm
388utility complains if it gets a read error.
389If
390.Fl y
391has been specified, or the user responds
392.Ql y ,
393.Nm
394will attempt to continue the restore.
395.Pp
396If a backup was made using more than one tape volume,
397.Nm
398will notify the user when it is time to mount the next volume.
399If the
400.Fl x
401or
402.Fl i
403flag has been specified,
404.Nm
405will also ask which volume the user wishes to mount.
406The fastest way to extract a few files is to
407start with the last volume, and work towards the first volume.
408.Pp
409There are numerous consistency checks that can be listed by
410.Nm .
411Most checks are self-explanatory or can ``never happen''.
412Common errors are given below.
413.Pp
414.Bl -tag -width Ds -compact
415.Pp
416.It <filename>: not found on tape
417The specified file name was listed in the tape directory,
418but was not found on the tape.
419This is caused by tape read errors while looking for the file,
420and from using a dump tape created on an active file system.
421.Pp
422.It expected next file <inumber>, got <inumber>
423A file that was not listed in the directory showed up.
424This can occur when using a dump created on an active file system.
425.Pp
426.It Incremental dump too low
427When doing incremental restore,
428a dump that was written before the previous incremental dump,
429or that has too low an incremental level has been loaded.
430.Pp
431.It Incremental dump too high
432When doing incremental restore,
433a dump that does not begin its coverage where the previous incremental
434dump left off,
435or that has too high an incremental level has been loaded.
436.Pp
437.It Tape read error while restoring <filename>
438.It Tape read error while skipping over inode <inumber>
439.It Tape read error while trying to resynchronize
440A tape (or other media) read error has occurred.
441If a file name is specified,
442then its contents are probably partially wrong.
443If an inode is being skipped or the tape is trying to resynchronize,
444then no extracted files have been corrupted,
445though files may not be found on the tape.
446.Pp
447.It resync restore, skipped <num> blocks
448After a dump read error,
449.Nm
450may have to resynchronize itself.
451This message lists the number of blocks that were skipped over.
452.El
453.Sh SEE ALSO
454.Xr dump 8 ,
455.Xr mount 8 ,
456.Xr newfs 8 ,
457.Xr rmt 8
458.Sh HISTORY
459The
460.Nm
461utility appeared in
462.Bx 4.2 .
463.Sh BUGS
464The
465.Nm
466utility can get confused when doing incremental restores from
467dumps that were made on active file systems without the
468.Fl L
469option (see
470.Xr dump 8 ) .
471.Pp
472A level zero dump must be done after a full restore.
473Because restore runs in user code,
474it has no control over inode allocation;
475thus a full dump must be done to get a new set of directories
476reflecting the new inode numbering,
477even though the contents of the files is unchanged.
478.Pp
479To do a network restore, you have to run restore as root.
480This is due
481to the previous security history of dump and restore.
482(restore is
483written to be setuid root, but we are not certain all bugs are gone
484from the restore code - run setuid at your own risk.)
485.Pp
486The temporary files
487.Pa /tmp/rstdir*
488and
489.Pa /tmp/rstmode*
490are generated with a unique name based on the date of the dump
491and the process ID (see
492.Xr mktemp 3 ) ,
493except for when
494.Fl r
495or
496.Fl R
497is used.
498Because
499.Fl R
500allows you to restart a
501.Fl r
502operation that may have been interrupted, the temporary files should
503be the same across different processes.
504In all other cases, the files are unique because it is possible to
505have two different dumps started at the same time, and separate
506operations should not conflict with each other.
507