xref: /netbsd/sbin/restore/restore.8 (revision bf9ec67e)
1.\"	$NetBSD: restore.8,v 1.35 2002/02/08 01:30:46 ross Exp $
2.\"
3.\" Copyright (c) 1985, 1991, 1993
4.\"	The Regents of the University of California.  All rights reserved.
5.\"
6.\" Redistribution and use in source and binary forms, with or without
7.\" modification, are permitted provided that the following conditions
8.\" are met:
9.\" 1. Redistributions of source code must retain the above copyright
10.\"    notice, this list of conditions and the following disclaimer.
11.\" 2. Redistributions in binary form must reproduce the above copyright
12.\"    notice, this list of conditions and the following disclaimer in the
13.\"    documentation and/or other materials provided with the distribution.
14.\" 3. All advertising materials mentioning features or use of this software
15.\"    must display the following acknowledgement:
16.\"	This product includes software developed by the University of
17.\"	California, Berkeley and its contributors.
18.\" 4. Neither the name of the University nor the names of its contributors
19.\"    may be used to endorse or promote products derived from this software
20.\"    without specific prior written permission.
21.\"
22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32.\" SUCH DAMAGE.
33.\"
34.\"     @(#)restore.8	8.4 (Berkeley) 5/1/95
35.\"
36.Dd July 1, 1997
37.Dt RESTORE 8
38.Os
39.Sh NAME
40.Nm restore ,
41.Nm rrestore
42.Nd "restore files or file systems from backups made with dump"
43.Sh SYNOPSIS
44.Nm
45.Fl i
46.Op Fl cdhmuvyN
47.Op Fl b Ar blocksize
48.Op Fl f Ar file
49.Op Fl s Ar fileno
50.Nm ""
51.Fl R
52.Op Fl cduvyN
53.Op Fl b Ar blocksize
54.Op Fl f Ar file
55.Op Fl s Ar fileno
56.Nm ""
57.Fl r
58.Op Fl cduvyN
59.Op Fl b Ar blocksize
60.Op Fl f Ar file
61.Op Fl s Ar fileno
62.Nm ""
63.Fl t
64.Op Fl cdhuvy
65.Op Fl b Ar blocksize
66.Op Fl f Ar file
67.Op Fl s Ar fileno
68.Op Ar
69.Nm ""
70.Fl x
71.Op Fl cdhmuvyN
72.Op Fl b Ar blocksize
73.Op Fl f Ar file
74.Op Fl s Ar fileno
75.Op Ar
76.Pp
77.in -\n(iSu
78(The
79.Bx 4.3
80option syntax is implemented for backward compatibility, but
81is not documented here.)
82.Sh DESCRIPTION
83The
84.Nm
85command performs the inverse function of
86.Xr dump 8 .
87A full backup of a file system may be restored and
88subsequent incremental backups layered on top of it.
89Single files and
90directory subtrees may be restored from full or partial
91backups.
92.Nm
93works across a network;
94to do this see the
95.Fl f
96flag described below.
97Other arguments to the command are file or directory
98names specifying the files that are to be restored.
99Unless the
100.Fl h
101flag is specified (see below),
102the appearance of a directory name refers to
103the files and (recursively) subdirectories of that directory.
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.
144.Nm
145will 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 , Ic xit
159Restore immediately exits,
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
177List dump header information.
178.It Ic Debug
179Enable debugging.
180.El
181.It Fl R
182.Nm
183requests 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 level 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/rrp0g eagle
209mount /dev/rp0g /mnt
210cd /mnt
211
212restore rf /dev/rst8
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
224.Nm "" ,
225in conjunction with
226.Xr newfs 8
227and
228.Xr dump 8 ,
229may be used to modify file system parameters
230such as size or block size.
231.It Fl t
232The names of the specified files are listed if they occur
233on the backup.
234If no file argument is given,
235then the root directory is listed,
236which results in the entire content of the
237backup being listed,
238unless the
239.Fl h
240flag has been specified.
241Note that the
242.Fl t
243flag replaces the function of the old
244.Ic dumpdir
245program.
246.ne 1i
247.It Fl x
248The named files are read from the given media.
249If a named file matches a directory whose contents
250are on the backup
251and the
252.Fl h
253flag is not specified,
254the directory is recursively extracted.
255The owner, modification time,
256and mode are restored (if possible).
257If no file argument is given,
258then the root directory is extracted,
259which results in the entire content of the
260backup being extracted,
261unless the
262.Fl h
263flag has been specified.
264.El
265.Pp
266The following additional options may be specified:
267.Bl -tag -width Ds
268.It Fl b Ar blocksize
269The number of kilobytes per dump record.
270If the
271.Fl b
272option is not specified,
273.Nm
274tries to determine the block size dynamically.
275.It Fl c
276Normally,
277.Nm
278will try to determine dynamically whether the dump was made from an
279old (pre-4.4) or new format file sytem.
280The
281.Fl c
282flag disables this check, and only allows reading a dump in the old
283format.
284.It Fl d
285Enable debugging.
286.It Fl f Ar file
287Read the backup from
288.Ar file ;
289.Ar file
290may be a special device file
291like
292.Pa /dev/rst0
293(a tape drive),
294.Pa /dev/rsd1c
295(a disk drive),
296an ordinary file,
297or
298.Ql Fl
299(the standard input).
300If the name of the file is of the form
301.Dq host:file ,
302or
303.Dq user@host:file ,
304.Nm
305reads from the named file on the remote host using
306.Xr rmt 8 .
307If the name of the file is
308.Ql Fl ,
309.Nm
310reads from standard input.
311Thus,
312.Xr dump 8
313and
314.Nm
315can be used in a pipeline to dump and restore a file system
316with the command
317.Bd -literal -offset indent
318dump 0f - /usr | (cd /mnt; restore xf -)
319.Ed
320.Pp
321.It Fl h
322Extract the actual directory,
323rather than the files that it references.
324This prevents hierarchical restoration of complete subtrees
325from the dump.
326.It Fl m
327Extract by inode numbers rather than by file name.
328This is useful if only a few files are being extracted,
329and one wants to avoid regenerating the complete pathname
330to the file.
331.It Fl s Ar fileno
332Read from the specified
333.Ar fileno
334on a multi-file tape.
335File numbering starts at 1.
336.It Fl u
337The
338.Fl u
339(unlink)
340flag removes files before extracting them.
341This is useful when an executable file is in use.
342Ignored if
343.Fl t
344or
345.Fl N
346flag is given.
347.It Fl v
348Normally
349.Nm
350does its work silently.
351The
352.Fl v
353(verbose)
354flag causes it to type the name of each file it treats
355preceded by its file type.
356.It Fl y
357Do not ask the user whether to abort the restore in the event of an error.
358Always try to skip over the bad block(s) and continue.
359.It Fl N
360Do not perform actual writing to disk.
361.El
362.Sh ENVIRONMENT
363If the following environment variable exists it will be utilized by
364.Nm "" :
365.Bl -tag -width "TMPDIR" -compact
366.It TMPDIR
367The directory given in TMPDIR will be used
368instead of
369.Pa /tmp
370to store temporary files.
371Refer to
372.Xr environ 7
373for more information.
374.El
375.Sh FILES
376.Bl -tag -width "./restoresymtable" -compact
377.It Pa /dev/nrst0
378default tape unit to use.
379Taken from
380.Dv _PATH_DEFTAPE
381in
382.Pa /usr/include/paths.h .
383.It Pa /dev/rst*
384raw SCSI tape interface
385.It Pa /tmp/rstdir*
386file containing directories on the tape.
387.It Pa /tmp/rstmode*
388owner, mode, and time stamps for directories.
389.It Pa \&./restoresymtable
390information passed between incremental restores.
391.El
392.Sh DIAGNOSTICS
393Complains if it gets a read error.
394If
395.Fl y
396has been specified, or the user responds
397.Ql y ,
398.Nm
399will attempt to continue the restore.
400.Pp
401If a backup was made using more than one tape volume,
402.Nm
403will notify the user when it is time to mount the next volume.
404If the
405.Fl x
406or
407.Fl i
408flag has been specified,
409.Nm
410will also ask which volume the user wishes to mount.
411The fastest way to extract a few files is to
412start with the last volume, and work towards the first volume.
413.Pp
414There are numerous consistency checks that can be listed by
415.Nm "" .
416Most checks are self-explanatory or can ``never happen''.
417Common errors are given below.
418.Pp
419.Bl -tag -width Ds -compact
420.It Converting to new file system format.
421A dump tape created from the old file system has been loaded.
422It is automatically converted to the new file system format.
423.Pp
424.It \*[Lt]filename\*[Gt]: not found on tape
425The specified file name was listed in the tape directory,
426but was not found on the tape.
427This is caused by tape read errors while looking for the file,
428and from using a dump tape created on an active file system.
429.Pp
430.It expected next file \*[Lt]inumber\*[Gt], got \*[Lt]inumber\*[Gt]
431A file that was not listed in the directory showed up.
432This can occur when using a dump created on an active file system.
433.Pp
434.It Incremental dump too low
435When doing incremental restore,
436a dump that was written before the previous incremental dump,
437or that has too low an incremental level has been loaded.
438.Pp
439.It Incremental dump too high
440When doing incremental restore,
441a dump that does not begin its coverage where the previous incremental
442dump left off,
443or that has too high an incremental level has been loaded.
444.Pp
445.It Tape read error while restoring \*[Lt]filename\*[Gt]
446.It Tape read error while skipping over inode \*[Lt]inumber\*[Gt]
447.It Tape read error while trying to resynchronize
448A tape (or other media) read error has occurred.
449If a file name is specified,
450then its contents are probably partially wrong.
451If an inode is being skipped or the tape is trying to resynchronize,
452then no extracted files have been corrupted,
453though files may not be found on the tape.
454.Pp
455.It resync restore, skipped \*[Lt]num\*[Gt] blocks
456After a dump read error,
457.Nm
458may have to resynchronize itself.
459This message lists the number of blocks that were skipped over.
460.El
461.Sh SEE ALSO
462.Xr environ 7 ,
463.Xr dump 8 ,
464.Xr mount 8 ,
465.Xr newfs 8 ,
466.Xr rmt 8
467.Sh HISTORY
468The
469.Nm
470command appeared in
471.Bx 4.2 .
472.Sh BUGS
473.Nm
474can get confused when doing incremental restores from
475dumps that were made on active file systems.
476.Pp
477A level zero dump must be done after a full restore.
478Because
479.Nm
480runs in user code,
481it has no control over inode allocation;
482thus a full dump must be done to get a new set of directories
483reflecting the new inode numbering,
484even though the content of the files is unchanged.
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 shouldn't conflict with each other.
507