xref: /freebsd/sbin/restore/restore.8 (revision 6af83ee0d2941d18880b6aaa2b4facd1d30c6106)
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28.\"     @(#)restore.8	8.4 (Berkeley) 5/1/95
29.\" $FreeBSD$
30.\"
31.Dd May 1, 1995
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 cdhmNuvy
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 cdNuvy
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 cdNuvy
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 cdhNuvy
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 cdhmNuvy
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 c
280Normally,
281.Nm
282will try to determine dynamically whether the dump was made from an
283old (pre-4.4) or new format file system.
284The
285.Fl c
286flag disables this check, and only allows reading a dump in the old
287format.
288.It Fl d
289Sends verbose debugging output to the standard error.
290.It Fl f Ar file
291Read the backup from
292.Ar file ;
293.Ar file
294may be a special device file
295like
296.Pa /dev/sa0
297(a tape drive),
298.Pa /dev/da1c
299(a disk drive),
300an ordinary file,
301or
302.Sq Fl
303(the standard input).
304If the name of the file is of the form
305.Dq host:file ,
306or
307.Dq user@host:file ,
308.Nm
309reads from the named file on the remote host using
310.Xr rmt 8 .
311.It Fl P Ar pipecommand
312Use
313.Xr popen 3
314to execute the
315.Xr sh 1
316script string defined by
317.Ar pipecommand
318as the input for every volume in the backup.
319This child pipeline's
320.Dv stdout
321.Pq Pa /dev/fd/1
322is redirected to the
323.Nm
324input stream, and the environment variable
325.Ev RESTORE_VOLUME
326is set to the current volume number being read.
327The
328.Ar pipecommand
329script is started each time a volume is loaded, as if it were a tape drive.
330.It Fl h
331Extract the actual directory,
332rather than the files that it references.
333This prevents hierarchical restoration of complete subtrees
334from the dump.
335.It Fl m
336Extract by inode numbers rather than by file name.
337This is useful if only a few files are being extracted,
338and one wants to avoid regenerating the complete pathname
339to the file.
340.It Fl N
341Do the extraction normally, but do not actually write any changes
342to disk.
343This can be used to check the integrity of dump media
344or other test purposes.
345.It Fl s Ar fileno
346Read from the specified
347.Ar fileno
348on a multi-file tape.
349File numbering starts at 1.
350.It Fl u
351When creating certain types of files, restore may generate a warning
352diagnostic if they already exist in the target directory.
353To prevent this, the
354.Fl u
355(unlink) flag causes restore to remove old entries before attempting
356to create new ones.
357.It Fl v
358Normally
359.Nm
360does its work silently.
361The
362.Fl v
363(verbose)
364flag causes it to type the name of each file it treats
365preceded by its file type.
366.It Fl y
367Do not ask the user whether to abort the restore in the event of an error.
368Always try to skip over the bad block(s) and continue.
369.El
370.Sh ENVIRONMENT
371.Bl -tag -width ".Ev TMPDIR"
372.It Ev TAPE
373Device from which to read backup.
374.It Ev TMPDIR
375Name of directory where temporary files are to be created.
376.El
377.Sh FILES
378.Bl -tag -width "./restoresymtable" -compact
379.It Pa /dev/sa0
380the default tape drive
381.It Pa /tmp/rstdir*
382file containing directories on the tape.
383.It Pa /tmp/rstmode*
384owner, mode, and time stamps for directories.
385.It Pa \&./restoresymtable
386information passed between incremental restores.
387.El
388.Sh DIAGNOSTICS
389The
390.Nm
391utility complains if it gets a read error.
392If
393.Fl y
394has been specified, or the user responds
395.Ql y ,
396.Nm
397will attempt to continue the restore.
398.Pp
399If a backup was made using more than one tape volume,
400.Nm
401will notify the user when it is time to mount the next volume.
402If the
403.Fl x
404or
405.Fl i
406flag has been specified,
407.Nm
408will also ask which volume the user wishes to mount.
409The fastest way to extract a few files is to
410start with the last volume, and work towards the first volume.
411.Pp
412There are numerous consistency checks that can be listed by
413.Nm .
414Most checks are self-explanatory or can ``never happen''.
415Common errors are given below.
416.Pp
417.Bl -tag -width Ds -compact
418.It Converting to new file system format.
419A dump tape created from the old file system has been loaded.
420It is automatically converted to the new file system format.
421.Pp
422.It <filename>: not found on tape
423The specified file name was listed in the tape directory,
424but was not found on the tape.
425This is caused by tape read errors while looking for the file,
426and from using a dump tape created on an active file system.
427.Pp
428.It expected next file <inumber>, got <inumber>
429A file that was not listed in the directory showed up.
430This can occur when using a dump created on an active file system.
431.Pp
432.It Incremental dump too low
433When doing incremental restore,
434a dump that was written before the previous incremental dump,
435or that has too low an incremental level has been loaded.
436.Pp
437.It Incremental dump too high
438When doing incremental restore,
439a dump that does not begin its coverage where the previous incremental
440dump left off,
441or that has too high an incremental level has been loaded.
442.Pp
443.It Tape read error while restoring <filename>
444.It Tape read error while skipping over inode <inumber>
445.It Tape read error while trying to resynchronize
446A tape (or other media) read error has occurred.
447If a file name is specified,
448then its contents are probably partially wrong.
449If an inode is being skipped or the tape is trying to resynchronize,
450then no extracted files have been corrupted,
451though files may not be found on the tape.
452.Pp
453.It resync restore, skipped <num> blocks
454After a dump read error,
455.Nm
456may have to resynchronize itself.
457This message lists the number of blocks that were skipped over.
458.El
459.Sh SEE ALSO
460.Xr dump 8 ,
461.Xr mount 8 ,
462.Xr newfs 8 ,
463.Xr rmt 8
464.Sh HISTORY
465The
466.Nm
467utility appeared in
468.Bx 4.2 .
469.Sh BUGS
470The
471.Nm
472utility can get confused when doing incremental restores from
473dumps that were made on active file systems.
474.Pp
475A level zero dump must be done after a full restore.
476Because restore runs in user code,
477it has no control over inode allocation;
478thus a full dump must be done to get a new set of directories
479reflecting the new inode numbering,
480even though the contents of the files is unchanged.
481.Pp
482To do a network restore, you have to run restore as root.
483This is due
484to the previous security history of dump and restore.
485(restore is
486written to be setuid root, but we are not certain all bugs are gone
487from the restore code - run setuid at your own risk.)
488.Pp
489The temporary files
490.Pa /tmp/rstdir*
491and
492.Pa /tmp/rstmode*
493are generated with a unique name based on the date of the dump
494and the process ID (see
495.Xr mktemp 3 ) ,
496except for when
497.Fl r
498or
499.Fl R
500is used.
501Because
502.Fl R
503allows you to restart a
504.Fl r
505operation that may have been interrupted, the temporary files should
506be the same across different processes.
507In all other cases, the files are unique because it is possible to
508have two different dumps started at the same time, and separate
509operations should not conflict with each other.
510