xref: /dragonfly/sbin/restore/restore.8 (revision 73e0051e)
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32.\"     @(#)restore.8	8.4 (Berkeley) 5/1/95
33.\" $FreeBSD: src/sbin/restore/restore.8,v 1.20.2.15 2003/02/23 22:47:13 trhodes Exp $
34.\" $DragonFly: src/sbin/restore/restore.8,v 1.4 2006/04/17 18:01:37 swildner Exp $
35.\"
36.Dd May 1, 1995
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 cdhkmNuvy
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 cdkNuvy
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 cdkNuvy
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 cdhkNuvy
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 cdhkmNuvy
72.Op Fl b Ar blocksize
73.Op Fl f Ar file
74.Op Fl s Ar fileno
75.Op Ar
76.Pp
77.Nm rrestore
78is an alternate name for
79.Nm .
80.Pp
81.in \" XXX
82(The
83.Bx 4.3
84option syntax is implemented for backward compatibility, but
85is not documented here.)
86.Sh DESCRIPTION
87The
88.Nm
89utility performs the inverse function of
90.Xr dump 8 .
91A full backup of a file system may be restored and
92subsequent incremental backups layered on top of it.
93Single files and
94directory subtrees may be restored from full or partial
95backups.
96The
97.Nm
98utility works across a network;
99to do this see the
100.Fl f
101flag described below.
102Other arguments to the command are file or directory
103names specifying the files that are to be restored.
104Unless the
105.Fl h
106flag is specified (see below),
107the appearance of a directory name refers to
108the files and (recursively) subdirectories of that directory.
109.Pp
110Exactly one of the following flags is required:
111.Bl -tag -width Ds
112.It Fl i
113This mode allows interactive restoration of files from a dump.
114After reading in the directory information from the dump,
115.Nm
116provides a shell like interface that allows the user to move
117around the directory tree selecting files to be extracted.
118The available commands are given below;
119for those commands that require an argument,
120the default is the current directory.
121.Bl -tag -width Fl
122.It Ic add Op Ar arg
123The current directory or specified argument is added to the list of
124files to be extracted.
125If a directory is specified, then it and all its descendants are
126added to the extraction list
127(unless the
128.Fl h
129flag is specified on the command line).
130Files that are on the extraction list are prepended with a ``*''
131when they are listed by
132.Ic ls .
133.It Ic \&cd Ar arg
134Change the current working directory to the specified argument.
135.It Ic delete Op Ar arg
136The current directory or specified argument is deleted from the list of
137files to be extracted.
138If a directory is specified, then it and all its descendants are
139deleted from the extraction list
140(unless the
141.Fl h
142flag is specified on the command line).
143The most expedient way to extract most of the files from a directory
144is to add the directory to the extraction list and then delete
145those files that are not needed.
146.It Ic extract
147All the files that are on the extraction list are extracted
148from the dump.
149The
150.Nm
151utility will ask which volume the user wishes to mount.
152The fastest way to extract a few files is to
153start with the last volume, and work towards the first volume.
154.It Ic help
155List a summary of the available commands.
156.It Ic \&ls Op Ar arg
157List the current or specified directory.
158Entries that are directories are appended with a ``/''.
159Entries that have been marked for extraction are prepended with a ``*''.
160If the verbose
161flag is set the inode number of each entry is also listed.
162.It Ic pwd
163Print the full pathname of the current working directory.
164.It Ic quit
165Exit immediately,
166even if the extraction list is not empty.
167.It Ic setmodes
168All the directories that have been added to the extraction list
169have their owner, modes, and times set;
170nothing is extracted from the dump.
171This is useful for cleaning up after a restore has been prematurely aborted.
172.It Ic verbose
173The sense of the
174.Fl v
175flag is toggled.
176When set, the verbose flag causes the
177.Ic ls
178command to list the inode numbers of all entries.
179It also causes
180.Nm
181to print out information about each file as it is extracted.
182.It Ic what
183Display dump header information, which includes: date,
184level, label, and the file system and host dump was made
185from.
186.El
187.It Fl R
188Request a particular tape of a multi volume set on which to restart
189a full restore
190(see the
191.Fl r
192flag below).
193This is useful if the restore has been interrupted.
194.It Fl r
195Restore (rebuild a file system).
196The target file system should be made pristine with
197.Xr newfs 8 ,
198mounted and the user
199.Xr cd 1 Ns 'd
200into the pristine file system
201before starting the restoration of the initial level 0 backup.
202If the
203level 0 restores successfully, the
204.Fl r
205flag may be used to restore
206any necessary incremental backups on top of the level 0.
207The
208.Fl r
209flag precludes an interactive file extraction and can be
210detrimental to one's health if not used carefully (not to mention
211the disk). An example:
212.Bd -literal -offset indent
213newfs /dev/da0s1a
214mount /dev/da0s1a /mnt
215cd /mnt
216
217restore rf /dev/sa0
218.Ed
219.Pp
220Note that
221.Nm
222leaves a file
223.Pa restoresymtable
224in the root directory to pass information between incremental
225restore passes.
226This file should be removed when the last incremental has been
227restored.
228.Pp
229The
230.Nm
231utility ,
232in conjunction with
233.Xr newfs 8
234and
235.Xr dump 8 ,
236may be used to modify file system parameters
237such as size or block size.
238.It Fl t
239The names of the specified files are listed if they occur
240on the backup.
241If no file argument is given,
242then the root directory is listed,
243which results in the entire content of the
244backup being listed,
245unless the
246.Fl h
247flag has been specified.
248Note that the
249.Fl t
250flag replaces the function of the old
251.Xr dumpdir 8
252program.
253.It Fl x
254The named files are read from the given media.
255If a named file matches a directory whose contents
256are on the backup
257and the
258.Fl h
259flag is not specified,
260the directory is recursively extracted.
261The owner, modification time,
262and mode are restored (if possible).
263If no file argument is given,
264then the root directory is extracted,
265which results in the entire content of the
266backup being extracted,
267unless the
268.Fl h
269flag has been specified.
270.El
271.Pp
272The following additional options may be specified:
273.Bl -tag -width Ds
274.It Fl b Ar blocksize
275The number of kilobytes per dump record.
276If the
277.Fl b
278option is not specified,
279.Nm
280tries to determine the media block size dynamically.
281.It Fl c
282Normally,
283.Nm
284will try to determine dynamically whether the dump was made from an
285old (pre-4.4) or new format file system.  The
286.Fl c
287flag disables this check, and only allows reading a dump in the old
288format.
289.It Fl d
290Sends verbose debugging output to the standard error.
291.It Fl f Ar file
292Read the backup from
293.Ar file ;
294.Ar file
295may be a special device file
296like
297.Pa /dev/sa0
298(a tape drive),
299.Pa /dev/da1c
300(a disk drive),
301an ordinary file,
302or
303.Sq Fl
304(the standard input).
305If the name of the file is of the form
306.Dq host:file ,
307or
308.Dq user@host:file ,
309.Nm
310reads from the named file on the remote host using
311.Xr rmt 8 .
312.Pp
313.It Fl k
314Use Kerberos authentication when contacting the remote tape server.
315(Only available if this options was enabled when
316.Nm
317was compiled.)
318.Pp
319.It Fl h
320Extract the actual directory,
321rather than the files that it references.
322This prevents hierarchical restoration of complete subtrees
323from the dump.
324.It Fl m
325Extract by inode numbers rather than by file name.
326This is useful if only a few files are being extracted,
327and one wants to avoid regenerating the complete pathname
328to the file.
329.It Fl N
330Do the extraction normally, but do not actually write any changes
331to disk.
332This can be used to check the integrity of dump media
333or other test purposes.
334.It Fl s Ar fileno
335Read from the specified
336.Ar fileno
337on a multi-file tape.
338File numbering starts at 1.
339.It Fl u
340When creating certain types of files, restore may generate a warning
341diagnostic if they already exist in the target directory.
342To prevent this, the
343.Fl u
344(unlink) flag causes restore to remove old entries before attempting
345to create new ones.
346.It Fl v
347Normally
348.Nm
349does its work silently.
350The
351.Fl v
352(verbose)
353flag causes it to type the name of each file it treats
354preceded by its file type.
355.It Fl y
356Do not ask the user whether to abort the restore in the event of an error.
357Always try to skip over the bad block(s) and continue.
358.El
359.Sh ENVIRONMENT
360.Bl -tag -width ".Ev TMPDIR"
361.It Ev TAPE
362Device from which to read backup.
363.It Ev TMPDIR
364Name of directory where temporary files are to be created.
365.El
366.Sh FILES
367.Bl -tag -width "./restoresymtable" -compact
368.It Pa /dev/sa0
369the default tape drive
370.It Pa /tmp/rstdir*
371file containing directories on the tape.
372.It Pa /tmp/rstmode*
373owner, mode, and time stamps for directories.
374.It Pa \&./restoresymtable
375information passed between incremental restores.
376.El
377.Sh DIAGNOSTICS
378The
379.Nm
380utility complains if it gets a read error.
381If
382.Fl y
383has been specified, or the user responds
384.Ql y ,
385.Nm
386will attempt to continue the restore.
387.Pp
388If a backup was made using more than one tape volume,
389.Nm
390will notify the user when it is time to mount the next volume.
391If the
392.Fl x
393or
394.Fl i
395flag has been specified,
396.Nm
397will also ask which volume the user wishes to mount.
398The fastest way to extract a few files is to
399start with the last volume, and work towards the first volume.
400.Pp
401There are numerous consistency checks that can be listed by
402.Nm .
403Most checks are self-explanatory or can ``never happen''.
404Common errors are given below.
405.Pp
406.Bl -tag -width Ds -compact
407.It Converting to new file system format.
408A dump tape created from the old file system has been loaded.
409It is automatically converted to the new file system format.
410.Pp
411.It <filename>: not found on tape
412The specified file name was listed in the tape directory,
413but was not found on the tape.
414This is caused by tape read errors while looking for the file,
415and from using a dump tape created on an active file system.
416.Pp
417.It expected next file <inumber>, got <inumber>
418A file that was not listed in the directory showed up.
419This can occur when using a dump created on an active file system.
420.Pp
421.It Incremental dump too low
422When doing incremental restore,
423a dump that was written before the previous incremental dump,
424or that has too low an incremental level has been loaded.
425.Pp
426.It Incremental dump too high
427When doing incremental restore,
428a dump that does not begin its coverage where the previous incremental
429dump left off,
430or that has too high an incremental level has been loaded.
431.Pp
432.It Tape read error while restoring <filename>
433.It Tape read error while skipping over inode <inumber>
434.It Tape read error while trying to resynchronize
435A tape (or other media) read error has occurred.
436If a file name is specified,
437then its contents are probably partially wrong.
438If an inode is being skipped or the tape is trying to resynchronize,
439then no extracted files have been corrupted,
440though files may not be found on the tape.
441.Pp
442.It resync restore, skipped <num> blocks
443After a dump read error,
444.Nm
445may have to resynchronize itself.
446This message lists the number of blocks that were skipped over.
447.El
448.Sh SEE ALSO
449.Xr dump 8 ,
450.Xr mount 8 ,
451.Xr newfs 8 ,
452.Xr rmt 8
453.Sh HISTORY
454The
455.Nm
456utility appeared in
457.Bx 4.2 .
458.Sh BUGS
459The
460.Nm
461utility can get confused when doing incremental restores from
462dumps that were made on active file systems.
463.Pp
464A level zero dump must be done after a full restore.
465Because restore runs in user code,
466it has no control over inode allocation;
467thus a full dump must be done to get a new set of directories
468reflecting the new inode numbering,
469even though the contents of the files is unchanged.
470.Pp
471To do a network restore, you have to run restore as root.  This is due
472to the previous security history of dump and restore.  (restore is
473written to be setuid root, but we are not certain all bugs are gone
474from the restore code - run setuid at your own risk.)
475.Pp
476The temporary files
477.Pa /tmp/rstdir*
478and
479.Pa /tmp/rstmode*
480are generated with a unique name based on the date of the dump
481and the process ID (see
482.Xr mktemp 3 ) ,
483except for when
484.Fl r
485or
486.Fl R
487is used.
488Because
489.Fl R
490allows you to restart a
491.Fl r
492operation that may have been interrupted, the temporary files should
493be the same across different processes.
494In all other cases, the files are unique because it is possible to
495have two different dumps started at the same time, and separate
496operations shouldn't conflict with each other.
497