xref: /freebsd/sbin/restore/restore.8 (revision 17d6c636720d00f77e5d098daf4c278f89d84f7b)
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32.\"     @(#)restore.8	8.4 (Berkeley) 5/1/95
33.\" $FreeBSD$
34.\"
35.Dd May 1, 1995
36.Dt RESTORE 8
37.Os
38.Sh NAME
39.Nm restore ,
40.Nm rrestore
41.Nd "restore files or file systems from backups made with dump"
42.Sh SYNOPSIS
43.Nm
44.Fl i
45.Op Fl cdhkmNuvy
46.Op Fl b Ar blocksize
47.Op Fl f Ar file
48.Op Fl s Ar fileno
49.Nm
50.Fl R
51.Op Fl cdkNuvy
52.Op Fl b Ar blocksize
53.Op Fl f Ar file
54.Op Fl s Ar fileno
55.Nm
56.Fl r
57.Op Fl cdkNuvy
58.Op Fl b Ar blocksize
59.Op Fl f Ar file
60.Op Fl s Ar fileno
61.Nm
62.Fl t
63.Op Fl cdhkNuvy
64.Op Fl b Ar blocksize
65.Op Fl f Ar file
66.Op Fl s Ar fileno
67.Op Ar
68.Nm
69.Fl x
70.Op Fl cdhkmNuvy
71.Op Fl b Ar blocksize
72.Op Fl f Ar file
73.Op Fl s Ar fileno
74.Op Ar
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
84command 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.
91.Nm Restore
92works across a network;
93to do this see the
94.Fl f
95flag described below.
96Other arguments to the command are file or directory
97names specifying the files that are to be restored.
98Unless the
99.Fl h
100flag is specified (see below),
101the appearance of a directory name refers to
102the files and (recursively) subdirectories of that directory.
103.Pp
104Exactly one of the following flags is required:
105.Bl -tag -width Ds
106.It Fl i
107This mode allows interactive restoration of files from a dump.
108After reading in the directory information from the dump,
109.Nm
110provides a shell like interface that allows the user to move
111around the directory tree selecting files to be extracted.
112The available commands are given below;
113for those commands that require an argument,
114the default is the current directory.
115.Bl -tag -width Fl
116.It Ic add Op Ar arg
117The current directory or specified argument is added to the list of
118files to be extracted.
119If a directory is specified, then it and all its descendents are
120added to the extraction list
121(unless the
122.Fl h
123flag is specified on the command line).
124Files that are on the extraction list are prepended with a ``*''
125when they are listed by
126.Ic ls .
127.It Ic \&cd Ar arg
128Change the current working directory to the specified argument.
129.It Ic delete Op Ar arg
130The current directory or specified argument is deleted from the list of
131files to be extracted.
132If a directory is specified, then it and all its descendents are
133deleted from the extraction list
134(unless the
135.Fl h
136flag is specified on the command line).
137The most expedient way to extract most of the files from a directory
138is to add the directory to the extraction list and then delete
139those files that are not needed.
140.It Ic extract
141All the files that are on the extraction list are extracted
142from the dump.
143.Nm Restore
144will ask which volume the user wishes to mount.
145The fastest way to extract a few files is to
146start with the last volume, and work towards the first volume.
147.It Ic help
148List a summary of the available commands.
149.It Ic \&ls Op Ar arg
150List the current or specified directory.
151Entries that are directories are appended with a ``/''.
152Entries that have been marked for extraction are prepended with a ``*''.
153If the verbose
154flag is set the inode number of each entry is also listed.
155.It Ic pwd
156Print the full pathname of the current working directory.
157.It Ic quit
158Restore immediately exits,
159even if the extraction list is not empty.
160.It Ic setmodes
161All the directories that have been added to the extraction list
162have their owner, modes, and times set;
163nothing is extracted from the dump.
164This is useful for cleaning up after a restore has been prematurely aborted.
165.It Ic verbose
166The sense of the
167.Fl v
168flag is toggled.
169When set, the verbose flag causes the
170.Ic ls
171command to list the inode numbers of all entries.
172It also causes
173.Nm
174to print out information about each file as it is extracted.
175.It Ic what
176Displays dump header information, which includes: date,
177level, label, and the filesystem and host dump was made
178from.
179.El
180.It Fl R
181.Nm Restore
182requests a particular tape of a multi volume set on which to restart
183a full restore
184(see the
185.Fl r
186flag below).
187This is useful if the restore has been interrupted.
188.It Fl r
189Restore (rebuild a file system).
190The target file system should be made pristine with
191.Xr newfs 8 ,
192mounted and the user
193.Xr cd Ns 'd
194into the pristine file system
195before starting the restoration of the initial level 0 backup.
196If the
197level 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). An example:
206.Bd -literal -offset indent
207newfs /dev/da0s1a
208mount /dev/da0s1a /mnt
209cd /mnt
210
211restore rf /dev/sa0
212.Ed
213.Pp
214Note that
215.Nm
216leaves a file
217.Pa restoresymtable
218in the root directory to pass information between incremental
219restore passes.
220This file should be removed when the last incremental has been
221restored.
222.Pp
223.Nm Restore ,
224in conjunction with
225.Xr newfs 8
226and
227.Xr dump 8 ,
228may be used to modify file system parameters
229such as size or block size.
230.It Fl t
231The names of the specified files are listed if they occur
232on the backup.
233If no file argument is given,
234then the root directory is listed,
235which results in the entire content of the
236backup being listed,
237unless the
238.Fl h
239flag has been specified.
240Note that the
241.Fl t
242flag replaces the function of the old
243.Xr dumpdir 8
244program.
245.It Fl x
246The named files are read from the given media.
247If a named file matches a directory whose contents
248are on the backup
249and the
250.Fl h
251flag is not specified,
252the directory is recursively extracted.
253The owner, modification time,
254and mode are restored (if possible).
255If no file argument is given,
256then the root directory is extracted,
257which results in the entire content of the
258backup being extracted,
259unless the
260.Fl h
261flag has been specified.
262.El
263.Pp
264The following additional options may be specified:
265.Bl -tag -width Ds
266.It Fl b Ar blocksize
267The number of kilobytes per dump record.
268If the
269.Fl b
270option is not specified,
271.Nm
272tries to determine the media block size dynamically.
273.It Fl c
274Normally,
275.Nm
276will try to determine dynamically whether the dump was made from an
277old (pre-4.4) or new format file system.  The
278.Fl c
279flag disables this check, and only allows reading a dump in the old
280format.
281.It Fl d
282Sends verbose debugging output to the standard error.
283.It Fl f Ar file
284Read the backup from
285.Ar file ;
286.Ar file
287may be a special device file
288like
289.Pa /dev/sa0
290(a tape drive),
291.Pa /dev/da1c
292(a disk drive),
293an ordinary file,
294or
295.Ql Fl
296(the standard input).
297If the name of the file is of the form
298.Dq host:file ,
299or
300.Dq user@host:file ,
301.Nm
302reads from the named file on the remote host using
303.Xr rmt 8 .
304.Pp
305.It Fl k
306Use Kerberos authentication when contacting the remote tape server.
307(Only available if this options was enabled when
308.Nm
309was compiled.)
310.Pp
311.It Fl h
312Extract the actual directory,
313rather than the files that it references.
314This prevents hierarchical restoration of complete subtrees
315from the dump.
316.It Fl m
317Extract by inode numbers rather than by file name.
318This is useful if only a few files are being extracted,
319and one wants to avoid regenerating the complete pathname
320to the file.
321.It Fl N
322Do the extraction normally, but do not actually write any changes
323to disk.
324This can be used to check the integrity of dump media
325or other test purposes.
326.It Fl s Ar fileno
327Read from the specified
328.Ar fileno
329on a multi-file tape.
330File numbering starts at 1.
331.It Fl u
332When creating certain types of files, restore may generate a warning
333diagnostic if they already exist in the target directory.
334To prevent this, the
335.Fl u
336(unlink) flag causes restore to remove old entries before attempting
337to create new ones.
338.It Fl v
339Normally
340.Nm
341does its work silently.
342The
343.Fl v
344(verbose)
345flag causes it to type the name of each file it treats
346preceded by its file type.
347.It Fl y
348Do not ask the user whether to abort the restore in the event of an error.
349Always try to skip over the bad block(s) and continue.
350.El
351.Sh DIAGNOSTICS
352.Nm
353complains if it gets a read error.
354If
355.Fl y
356has been specified, or the user responds
357.Ql y ,
358.Nm
359will attempt to continue the restore.
360.Pp
361If a backup was made using more than one tape volume,
362.Nm
363will notify the user when it is time to mount the next volume.
364If the
365.Fl x
366or
367.Fl i
368flag has been specified,
369.Nm
370will also ask which volume the user wishes to mount.
371The fastest way to extract a few files is to
372start with the last volume, and work towards the first volume.
373.Pp
374There are numerous consistency checks that can be listed by
375.Nm .
376Most checks are self-explanatory or can ``never happen''.
377Common errors are given below.
378.Pp
379.Bl -tag -width Ds -compact
380.It Converting to new file system format.
381A dump tape created from the old file system has been loaded.
382It is automatically converted to the new file system format.
383.Pp
384.It <filename>: not found on tape
385The specified file name was listed in the tape directory,
386but was not found on the tape.
387This is caused by tape read errors while looking for the file,
388and from using a dump tape created on an active file system.
389.Pp
390.It expected next file <inumber>, got <inumber>
391A file that was not listed in the directory showed up.
392This can occur when using a dump created on an active file system.
393.Pp
394.It Incremental dump too low
395When doing incremental restore,
396a dump that was written before the previous incremental dump,
397or that has too low an incremental level has been loaded.
398.Pp
399.It Incremental dump too high
400When doing incremental restore,
401a dump that does not begin its coverage where the previous incremental
402dump left off,
403or that has too high an incremental level has been loaded.
404.Pp
405.It Tape read error while restoring <filename>
406.It Tape read error while skipping over inode <inumber>
407.It Tape read error while trying to resynchronize
408A tape (or other media) read error has occurred.
409If a file name is specified,
410then its contents are probably partially wrong.
411If an inode is being skipped or the tape is trying to resynchronize,
412then no extracted files have been corrupted,
413though files may not be found on the tape.
414.Pp
415.It resync restore, skipped <num> blocks
416After a dump read error,
417.Nm
418may have to resynchronize itself.
419This message lists the number of blocks that were skipped over.
420.El
421.Sh FILES
422.Bl -tag -width "./restoresymtable" -compact
423.It Pa /dev/sa0
424the default tape drive
425.It Pa /tmp/rstdir*
426file containing directories on the tape.
427.It Pa /tmp/rstmode*
428owner, mode, and time stamps for directories.
429.It Pa \&./restoresymtable
430information passed between incremental restores.
431.El
432.Sh SEE ALSO
433.Xr dump 8 ,
434.Xr mount 8 ,
435.Xr newfs 8 ,
436.Xr rmt 8
437.Sh BUGS
438.Nm Restore
439can get confused when doing incremental restores from
440dumps that were made on active file systems.
441.Pp
442A level zero dump must be done after a full restore.
443Because restore runs in user code,
444it has no control over inode allocation;
445thus a full dump must be done to get a new set of directories
446reflecting the new inode numbering,
447even though the contents of the files is unchanged.
448.Pp
449To do a network restore, you have to run restore as root.  This is due
450to the previous security history of dump and restore.  (restore is
451written to be setuid root, but we are not certain all bugs are gone
452from the restore code - run setuid at your own risk.)
453.Pp
454The temporary files
455.Pa /tmp/rstdir*
456and
457.Pa /tmp/rstmode*
458are generated with a unique name based on the date of the dump
459and the process ID (see
460.Xr mktemp 3 ) ,
461except for when
462.Fl r
463or
464.Fl R
465is used.
466Because
467.Fl R
468allows you to restart a
469.Fl r
470operation that may have been interrupted, the temporary files should
471be the same across different processes.
472In all other cases, the files are unique because it is possible to
473have two different dumps started at the same time, and separate
474operations shouldn't conflict with each other.
475.Sh HISTORY
476The
477.Nm
478command appeared in
479.Bx 4.2 .
480