xref: /freebsd/sbin/restore/restore.8 (revision dd41de95a84d979615a2ef11df6850622bf6184e)
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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.Sh DESCRIPTION
72The
73.Nm
74utility performs the inverse function of
75.Xr dump 8 .
76A full backup of a file system may be restored and
77subsequent incremental backups layered on top of it.
78Single files and
79directory subtrees may be restored from full or partial
80backups.
81The
82.Nm
83utility works across a network;
84to do this see the
85.Fl f
86and
87.Fl P
88flags described below.
89Other arguments to the command are file or directory
90names specifying the files that are to be restored.
91Unless the
92.Fl h
93flag is specified (see below),
94the appearance of a directory name refers to
95the files and (recursively) subdirectories of that directory.
96.Pp
97.Nm
98may also be invoked as
99.Nm rrestore .
100The
101.Bx 4.3
102option syntax is implemented for backward compatibility, but
103is not documented here.
104.Pp
105Exactly one of the following flags is required:
106.Bl -tag -width Ds
107.It Fl i
108This mode allows interactive restoration of files from a dump.
109After reading in the directory information from the dump,
110.Nm
111provides a shell like interface that allows the user to move
112around the directory tree selecting files to be extracted.
113The available commands are given below;
114for those commands that require an argument,
115the default is the current directory.
116.Bl -tag -width Fl
117.It Ic add Op Ar arg
118The current directory or specified argument is added to the list of
119files to be extracted.
120If a directory is specified, then it and all its descendents are
121added to the extraction list
122(unless the
123.Fl h
124flag is specified on the command line).
125Files that are on the extraction list are prepended with a ``*''
126when they are listed by
127.Ic ls .
128.It Ic \&cd Ar arg
129Change the current working directory to the specified argument.
130.It Ic delete Op Ar arg
131The current directory or specified argument is deleted from the list of
132files to be extracted.
133If a directory is specified, then it and all its descendents are
134deleted from the extraction list
135(unless the
136.Fl h
137flag is specified on the command line).
138The most expedient way to extract most of the files from a directory
139is to add the directory to the extraction list and then delete
140those files that are not needed.
141.It Ic extract
142All the files that are on the extraction list are extracted
143from the dump.
144The
145.Nm
146utility will ask which volume the user wishes to mount.
147The fastest way to extract a few files is to
148start with the last volume, and work towards the first volume.
149.It Ic help
150List a summary of the available commands.
151.It Ic \&ls Op Ar arg
152List the current or specified directory.
153Entries that are directories are appended with a ``/''.
154Entries that have been marked for extraction are prepended with a ``*''.
155If the verbose
156flag is set the inode number of each entry is also listed.
157.It Ic pwd
158Print the full pathname of the current working directory.
159.It Ic quit
160Exit immediately,
161even if the extraction list is not empty.
162.It Ic setmodes
163All the directories that have been added to the extraction list
164have their owner, modes, and times set;
165nothing is extracted from the dump.
166This is useful for cleaning up after a restore has been prematurely aborted.
167.It Ic verbose
168The sense of the
169.Fl v
170flag is toggled.
171When set, the verbose flag causes the
172.Ic ls
173command to list the inode numbers of all entries.
174It also causes
175.Nm
176to print out information about each file as it is extracted.
177.It Ic what
178Display dump header information, which includes: date,
179level, label, and the file system and host dump was made
180from.
181.El
182.It Fl R
183Request a particular tape of a multi volume set on which to restart
184a full restore
185(see the
186.Fl r
187flag below).
188This is useful if the restore has been interrupted.
189.It Fl r
190Restore (rebuild a file system).
191The target file system should be made pristine with
192.Xr newfs 8 ,
193mounted and the user
194.Xr cd 1 Ns 'd
195into the pristine file system
196before starting the restoration of the initial level 0 backup.
197If the
198level 0 restores successfully, the
199.Fl r
200flag may be used to restore
201any necessary incremental backups on top of the level 0.
202The
203.Fl r
204flag precludes an interactive file extraction and can be
205detrimental to one's health if not used carefully (not to mention
206the disk).
207An example:
208.Bd -literal -offset indent
209newfs /dev/da0s1a
210mount /dev/da0s1a /mnt
211cd /mnt
212
213restore rf /dev/sa0
214.Ed
215.Pp
216Note that
217.Nm
218leaves a file
219.Pa restoresymtable
220in the root directory to pass information between incremental
221restore passes.
222This file should be removed when the last incremental has been
223restored.
224.Pp
225The
226.Nm
227utility ,
228in conjunction with
229.Xr newfs 8
230and
231.Xr dump 8 ,
232may be used to modify file system parameters
233such as size or block size.
234.It Fl t
235The names of the specified files are listed if they occur
236on the backup.
237If no file argument is given,
238then the root directory is listed,
239which results in the entire content of the
240backup being listed,
241unless the
242.Fl h
243flag has been specified.
244Note that the
245.Fl t
246flag replaces the function of the old
247.Xr dumpdir 8
248program.
249.It Fl x
250The named files are read from the given media.
251If a named file matches a directory whose contents
252are on the backup
253and the
254.Fl h
255flag is not specified,
256the directory is recursively extracted.
257The owner, modification time,
258and mode are restored (if possible).
259If no file argument is given,
260then the root directory is extracted,
261which results in the entire content of the
262backup being extracted,
263unless the
264.Fl h
265flag has been specified.
266.El
267.Pp
268The following additional options may be specified:
269.Bl -tag -width Ds
270.It Fl b Ar blocksize
271The number of kilobytes per dump record.
272If the
273.Fl b
274option is not specified,
275.Nm
276tries to determine the media block size dynamically.
277.It Fl d
278Sends verbose debugging output to the standard error.
279.It Fl D
280This puts
281.Nm
282into degraded mode,
283causing restore to operate less efficiently
284but to try harder to read corrupted backups.
285.It Fl f Ar file
286Read the backup from
287.Ar file ;
288.Ar file
289may be a special device file
290like
291.Pa /dev/sa0
292(a tape drive),
293.Pa /dev/da1c
294(a disk drive),
295an ordinary file,
296or
297.Sq Fl
298(the standard input).
299If the name of the file is of the form
300.Dq host:file ,
301or
302.Dq user@host:file ,
303.Nm
304reads from the named file on the remote host using
305.Xr rmt 8 .
306.It Fl P Ar pipecommand
307Use
308.Xr popen 3
309to execute the
310.Xr sh 1
311script string defined by
312.Ar pipecommand
313as the input for every volume in the backup.
314This child pipeline's
315.Dv stdout
316.Pq Pa /dev/fd/1
317is redirected to the
318.Nm
319input stream, and the environment variable
320.Ev RESTORE_VOLUME
321is set to the current volume number being read.
322The
323.Ar pipecommand
324script is started each time a volume is loaded, as if it were a tape drive.
325.It Fl h
326Extract the actual directory,
327rather than the files that it references.
328This prevents hierarchical restoration of complete subtrees
329from the dump.
330.It Fl m
331Extract by inode numbers rather than by file name.
332This is useful if only a few files are being extracted,
333and one wants to avoid regenerating the complete pathname
334to the file.
335.It Fl N
336Do the extraction normally, but do not actually write any changes
337to disk.
338This can be used to check the integrity of dump media
339or other test purposes.
340.It Fl s Ar fileno
341Read from the specified
342.Ar fileno
343on a multi-file tape.
344File numbering starts at 1.
345.It Fl u
346When creating certain types of files, restore may generate a warning
347diagnostic if they already exist in the target directory.
348To prevent this, the
349.Fl u
350(unlink) flag causes restore to remove old entries before attempting
351to create new ones.
352This flag is recommended when using extended attributes
353to avoid improperly accumulating attributes on pre-existing files.
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.It <filename>: not found on tape
416The specified file name was listed in the tape directory,
417but was not found on the tape.
418This is caused by tape read errors while looking for the file,
419and from using a dump tape created on an active file system.
420.Pp
421.It expected next file <inumber>, got <inumber>
422A file that was not listed in the directory showed up.
423This can occur when using a dump created on an active file system.
424.Pp
425.It Incremental dump too low
426When doing incremental restore,
427a dump that was written before the previous incremental dump,
428or that has too low an incremental level has been loaded.
429.Pp
430.It Incremental dump too high
431When doing incremental restore,
432a dump that does not begin its coverage where the previous incremental
433dump left off,
434or that has too high an incremental level has been loaded.
435.Pp
436.It Tape read error while restoring <filename>
437.It Tape read error while skipping over inode <inumber>
438.It Tape read error while trying to resynchronize
439A tape (or other media) read error has occurred.
440If a file name is specified,
441then its contents are probably partially wrong.
442If an inode is being skipped or the tape is trying to resynchronize,
443then no extracted files have been corrupted,
444though files may not be found on the tape.
445.Pp
446.It resync restore, skipped <num> blocks
447After a dump read error,
448.Nm
449may have to resynchronize itself.
450This message lists the number of blocks that were skipped over.
451.El
452.Sh SEE ALSO
453.Xr dump 8 ,
454.Xr mount 8 ,
455.Xr newfs 8 ,
456.Xr rmt 8
457.Sh HISTORY
458The
459.Nm
460utility appeared in
461.Bx 4.2 .
462.Sh BUGS
463The
464.Nm
465utility can get confused when doing incremental restores from
466dumps that were made on active file systems without the
467.Fl L
468option (see
469.Xr dump 8 ) .
470.Pp
471A level zero dump must be done after a full restore.
472Because restore runs in user code,
473it has no control over inode allocation;
474thus a full dump must be done to get a new set of directories
475reflecting the new inode numbering,
476even though the contents of the files is unchanged.
477.Pp
478To do a network restore, you have to run restore as root.
479This is due
480to the previous security history of dump and restore.
481(restore is
482written to be setuid root, but we are not certain all bugs are gone
483from the restore code - run setuid at your own risk.)
484.Pp
485The temporary files
486.Pa /tmp/rstdir*
487and
488.Pa /tmp/rstmode*
489are generated with a unique name based on the date of the dump
490and the process ID (see
491.Xr mktemp 3 ) ,
492except for when
493.Fl r
494or
495.Fl R
496is used.
497Because
498.Fl R
499allows you to restart a
500.Fl r
501operation that may have been interrupted, the temporary files should
502be the same across different processes.
503In all other cases, the files are unique because it is possible to
504have two different dumps started at the same time, and separate
505operations should not conflict with each other.
506