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32 .\" $Id: restore.8.in,v 1.11 2000/12/04 15:43:17 stelian Exp $
33 .\"
34 .Dd __DATE__
35 .Dt RESTORE 8
36 .Os "restore __VERSION__"
37 .Sh NAME
38 .Nm restore
39 .Nd "restore files or file systems from backups made with dump"
40 .Sh SYNOPSIS
41 .Nm restore
42 .Fl C
43 .Op Fl ckMvy
44 .Op Fl b Ar blocksize
45 .Op Fl D Ar filesystem
46 .Op Fl f Ar file
47 .Op Fl s Ar fileno
48 .Op Fl T Ar directory
49 .Nm restore
50 .Fl i
51 .Op Fl chkmMNuvy
52 .Op Fl b Ar blocksize
53 .Op Fl f Ar file
54 .Op Fl s Ar fileno
55 .Op Fl T Ar directory
56 .Nm restore
57 .Fl R
58 .Op Fl ckMNuvy
59 .Op Fl b Ar blocksize
60 .Op Fl f Ar file
61 .Op Fl s Ar fileno
62 .Op Fl T Ar directory
63 .Nm restore
64 .Fl r
65 .Op Fl ckMNuvy
66 .Op Fl b Ar blocksize
67 .Op Fl f Ar file
68 .Op Fl s Ar fileno
69 .Op Fl T Ar directory
70 .Nm restore
71 .Fl t
72 .Op Fl chkMNuvy
73 .Op Fl b Ar blocksize
74 .Op Fl f Ar file
75 .Op Fl s Ar fileno
76 .Op Fl T Ar directory
77 .Op Fl X Ar filelist
78 .Op file ...
79 .Nm restore
80 .Fl x
81 .Op Fl chkmMNuvy
82 .Op Fl b Ar blocksize
83 .Op Fl f Ar file
84 .Op Fl s Ar fileno
85 .Op Fl T Ar directory
86 .Op Fl X Ar filelist
87 .Op file ...
88 .Pp
89 .in
90 (The
91 .Bx 4.3
92 option syntax is implemented for backward compatibility but
93 is not documented here.)
94 .Sh DESCRIPTION
95 The
96 .Nm restore
97 command performs the inverse function of
98 .Xr dump 8 .
99 A full backup of a file system may be restored and
100 subsequent incremental backups layered on top of it.
101 Single files and
102 directory subtrees may be restored from full or partial
103 backups.
104 .Nm Restore
105 works across a network;
106 to do this see the
107 .Fl f
108 flag described below.
109 Other arguments to the command are file or directory
110 names specifying the files that are to be restored.
111 Unless the
112 .Fl h
113 flag is specified (see below),
114 the appearance of a directory name refers to
115 the files and (recursively) subdirectories of that directory.
116 .Pp
117 Exactly one of the following flags is required:
118 .Bl -tag -width Ds
119 .It Fl C
120 This mode allows comparison of files from a dump.
121 .Nm Restore
122 reads the backup and compares its contents with files present on the
123 disk.
124 It first changes its working directory to the root of the filesystem
125 that was dumped and compares the tape with the files in its new
126 current directory.
127 .It Fl i
128 This mode allows interactive restoration of files from a dump.
129 After reading in the directory information from the dump,
130 .Nm restore
131 provides a shell like interface that allows the user to move
132 around the directory tree selecting files to be extracted.
133 The available commands are given below;
134 for those commands that require an argument,
135 the default is the current directory.
136 .Bl -tag -width Fl
137 .It Ic add Op Ar arg
138 The current directory or specified argument is added to the list of
139 files to be extracted.
140 If a directory is specified, then it and all its descendents are
141 added to the extraction list
142 (unless the
143 .Fl h
144 flag is specified on the command line).
145 Files that are on the extraction list are prepended with a
146 .Dq \&*
147 when they are listed by
148 .Ic ls .
149 .It Ic \&cd Ar arg
150 Change the current working directory to the specified argument.
151 .It Ic delete Op Ar arg
152 The current directory or specified argument is deleted from the list of
153 files to be extracted.
154 If a directory is specified, then it and all its descendents are
155 deleted from the extraction list
156 (unless the
157 .Fl h
158 flag is specified on the command line).
159 The most expedient way to extract most of the files from a directory
160 is to add the directory to the extraction list and then delete
161 those files that are not needed.
162 .It Ic extract
163 All files on the extraction list are extracted
164 from the dump.
165 .Nm Restore
166 will ask which volume the user wishes to mount.
167 The fastest way to extract a few files is to
168 start with the last volume and work towards the first volume.
169 .It Ic help
170 List a summary of the available commands.
171 .It Ic \&ls Op Ar arg
172 List the current or specified directory.
173 Entries that are directories are appended with a
174 .Dq \&* .
175 Entries that have been marked for extraction are prepended with a ``*''.
176 If the verbose
177 flag is set, the inode number of each entry is also listed.
178 .It Ic pwd
179 Print the full pathname of the current working directory.
180 .It Ic quit
181 Restore immediately exits,
182 even if the extraction list is not empty.
183 .It Ic setmodes
184 All directories that have been added to the extraction list
185 have their owner, modes, and times set;
186 nothing is extracted from the dump.
187 This is useful for cleaning up after a restore has been prematurely aborted.
188 .It Ic verbose
189 The sense of the
190 .Fl v
191 flag is toggled.
192 When set, the verbose flag causes the
193 .Ic ls
194 command to list the inode numbers of all entries.
195 It also causes
196 .Nm restore
197 to print out information about each file as it is extracted.
198 .El
199 .It Fl R
200 .Nm Restore
201 requests a particular tape of a multi-volume set on which to restart
202 a full restore
203 (see the
204 .Fl r
205 flag below).
206 This is useful if the restore has been interrupted.
207 .It Fl r
208 Restore (rebuild) a file system.
209 The target file system should be made pristine with
210 .Xr mke2fs 8 ,
211 mounted, and the user
212 .Xr cd Ns 'd
213 into the pristine file system
214 before starting the restoration of the initial level 0 backup. If the
215 level 0 restores successfully, the
216 .Fl r
217 flag may be used to restore
218 any necessary incremental backups on top of the level 0.
219 The
220 .Fl r
221 flag precludes an interactive file extraction and can be
222 detrimental to one's health (not to mention the disk) if not used carefully.
223 An example:
224 .Bd -literal -offset indent
225 mke2fs /dev/sda1
226 mount /dev/sda1 /mnt
227 cd /mnt
228
229 restore rf /dev/st0
230 .Ed
231 .Pp
232 Note that
233 .Nm restore
234 leaves a file
235 .Pa restoresymtable
236 in the root directory to pass information between incremental
237 restore passes.
238 This file should be removed when the last incremental has been
239 restored.
240 .Pp
241 .Nm Restore ,
242 in conjunction with
243 .Xr mke2fs 8
244 and
245 .Xr dump 8 ,
246 may be used to modify file system parameters
247 such as size or block size.
248 .It Fl t
249 The names of the specified files are listed if they occur
250 on the backup.
251 If no file argument is given,
252 the root directory is listed,
253 which results in the entire content of the
254 backup being listed,
255 unless the
256 .Fl h
257 flag has been specified.
258 Note that the
259 .Fl t
260 flag replaces the function of the old
261 .Xr dumpdir 8
262 program.
263 See also the
264 .Fl X
265 option below.
266 .ne 1i
267 .It Fl x
268 The named files are read from the given media.
269 If a named file matches a directory whose contents
270 are on the backup
271 and the
272 .Fl h
273 flag is not specified,
274 the directory is recursively extracted.
275 The owner, modification time,
276 and mode are restored (if possible).
277 If no file argument is given,
278 the root directory is extracted,
279 which results in the entire content of the
280 backup being extracted,
281 unless the
282 .Fl h
283 flag has been specified.
284 See also the
285 .Fl X
286 option below.
287 .El
288 .Pp
289 The following additional options may be specified:
290 .Bl -tag -width Ds
291 .It Fl b Ar blocksize
292 The number of kilobytes per dump record.
293 If the
294 .Fl b
295 option is not specified,
296 .Nm restore
297 tries to determine the media block size dynamically.
298 .It Fl c
299 Normally,
300 .Nm restore
301 will try to determine dynamically whether the dump was made from an
302 old (pre-4.4) or new format file system. The
303 .Fl c
304 flag disables this check, and only allows reading a dump in the old
305 format.
306 .It Fl D Ar filesystem
307 The
308 .Fl D
309 flag allows the user to specify the filesystem name when using
310 .Nm restore
311 with the
312 .Fl C
313 option to check the backup.
314 .It Fl f Ar file
315 Read the backup from
316 .Ar file ;
317 .Ar file
318 may be a special device file
319 like
320 .Pa /dev/st0
321 (a tape drive),
322 .Pa /dev/sda1
323 (a disk drive),
324 an ordinary file,
325 or
326 .Ql Fl
327 (the standard input).
328 If the name of the file is of the form
329 .Dq host:file
330 or
331 .Dq user@host:file ,
332 .Nm restore
333 reads from the named file on the remote host using
334 .Xr rmt 8 .
335 .Pp
336 .It Fl k
337 Use Kerberos authentication when contacting the remote tape server.
338 (Only available if this options was enabled when
339 .Nm restore
340 was compiled.)
341 .Pp
342 .It Fl h
343 Extract the actual directory,
344 rather than the files that it references.
345 This prevents hierarchical restoration of complete subtrees
346 from the dump.
347 .It Fl m
348 Extract by inode numbers rather than by file name.
349 This is useful if only a few files are being extracted,
350 and one wants to avoid regenerating the complete pathname
351 to the file.
352 .It Fl M
353 Enables the multi-volume feature (for reading dumps made using
354 the
355 .Fl M
356 option of dump). The name specified with
357 .Fl f
358 is treated as a prefix and
359 .Nm
360 tries to read in sequence from <prefix>001, <prefix>002 etc.
361 .It Fl N
362 The
363 .Fl N
364 flag causes
365 .Nm
366 to only print file names. Files are not extracted.
367 .It Fl s Ar fileno
368 Read from the specified
369 .Ar fileno
370 on a multi-file tape.
371 File numbering starts at 1.
372 .It Fl T Ar directory
373 The
374 .Fl T
375 flag allows the user to specify a directory to use for the storage of
376 temporary files. The default value is /tmp. This flag is most useful
377 when restoring files after having booted from a floppy. There might be little
378 or no space on the floppy filesystem, but another source of space might exist.
379 .It Fl u
380 When creating certain types of files, restore may generate a warning
381 diagnostic if they already exist in the target directory.
382 To prevent this, the
383 .Fl u
384 (unlink) flag causes restore to remove old entries before attempting
385 to create new ones.
386 .It Fl v
387 Normally
388 .Nm restore
389 does its work silently.
390 The
391 .Fl v
392 (verbose)
393 flag causes it to type the name of each file it treats
394 preceded by its file type.
395 .It Fl X Ar filelist
396 Read list of files to be listed or extracted from the text file
397 .Ar filelist
398 in addition to those specified on the command line. This can be used in
399 conjunction with the
400 .Fl t
401 or
402 .Fl x
403 commands. The file
404 .Ar filelist
405 should contain file names separated by newlines.
406 .Ar filelist
407 may be an ordinary file or
408 .Ql Fl
409 (the standard input).
410 .It Fl y
411 Do not ask the user whether to abort the restore in the event of an error.
412 Always try to skip over the bad block(s) and continue.
413 .El
414 .Sh DIAGNOSTICS
415 Complains if it gets a read error.
416 If
417 .Fl y
418 has been specified, or the user responds
419 .Ql y ,
420 .Nm restore
421 will attempt to continue the restore.
422 .Pp
423 If a backup was made using more than one tape volume,
424 .Nm restore
425 will notify the user when it is time to mount the next volume.
426 If the
427 .Fl x
428 or
429 .Fl i
430 flag has been specified,
431 .Nm restore
432 will also ask which volume the user wishes to mount.
433 The fastest way to extract a few files is to
434 start with the last volume, and work towards the first volume.
435 .Pp
436 There are numerous consistency checks that can be listed by
437 .Nm restore .
438 Most checks are self-explanatory or can
439 .Dq never happen .
440 Common errors are given below.
441 .Pp
442 .Bl -tag -width Ds -compact
443 .It Converting to new file system format
444 A dump tape created from the old file system has been loaded.
445 It is automatically converted to the new file system format.
446 .Pp
447 .It <filename>: not found on tape
448 The specified file name was listed in the tape directory,
449 but was not found on the tape.
450 This is caused by tape read errors while looking for the file,
451 and from using a dump tape created on an active file system.
452 .Pp
453 .It expected next file <inumber>, got <inumber>
454 A file that was not listed in the directory showed up.
455 This can occur when using a dump created on an active file system.
456 .Pp
457 .It Incremental dump too low
458 When doing an incremental restore,
459 a dump that was written before the previous incremental dump,
460 or that has too low an incremental level has been loaded.
461 .Pp
462 .It Incremental dump too high
463 When doing an incremental restore,
464 a dump that does not begin its coverage where the previous incremental
465 dump left off,
466 or that has too high an incremental level has been loaded.
467 .Pp
468 .It Tape read error while restoring <filename>
469 .It Tape read error while skipping over inode <inumber>
470 .It Tape read error while trying to resynchronize
471 A tape (or other media) read error has occurred.
472 If a file name is specified,
473 its contents are probably partially wrong.
474 If an inode is being skipped or the tape is trying to resynchronize,
475 no extracted files have been corrupted,
476 though files may not be found on the tape.
477 .Pp
478 .It resync restore, skipped <num> blocks
479 After a dump read error,
480 .Nm restore
481 may have to resynchronize itself.
482 This message lists the number of blocks that were skipped over.
483 .El
484 .Pp
485 .Nm Restore
486 exits with zero status on success.
487 Tape errors are indicated with an exit code of 1.
488 .Pp
489 When doing a comparison of files from a dump, an exit code
490 of 2 indicates that some files were modified or deleted since
491 the dump was made.
492 .Sh ENVIRONMENT
493 If the following environment variable exists it will be utilized by
494 .Nm restore :
495 .Pp
496 .Bl -tag -width "TMPDIR" -compact
497 .It Ev TAPE
498 If no -f option was specified,
499 .Nm
500 will use the device specified via
501 .Ev TAPE
502 as the dump device.
503 .Ev TAPE
504 may be of the form
505 .Qq tapename ,
506 .Qq host:tapename
507 or
508 .Qq user@host:tapename .
509 .It Ev TMPDIR
510 The directory given in
511 .Ev TMPDIR
512 will be used
513 instead of
514 .Pa /tmp
515 to store temporary files.
516 .It Ev RMT
517 The environment variable
518 .Ev RMT
519 will be used to determine the pathname of the remote
520 .Xr rmt 8
521 program.
522 .It Ev RSH
523 .Nm Restore
524 uses the contents of this variable to determine the name of the
525 remote shell command to use when doing a network restore (rsh, ssh etc.).
526 If this variable is not set,
527 .Xr rcmd 3
528 will be used, but only root will be able to do a network restore.
529 .Sh FILES
530 .Bl -tag -width "./restoresymtable" -compact
531 .It Pa /dev/st0
532 the default tape drive
533 .It Pa /tmp/rstdir*
534 file containing directories on the tape
535 .It Pa /tmp/rstmode*
536 owner, mode, and time stamps for directories
537 .It Pa \&./restoresymtable
538 information passed between incremental restores
539 .El
540 .Sh SEE ALSO
541 .Xr dump 8 ,
542 .Xr mount 8 ,
543 .Xr mke2fs 8 ,
544 .Xr rmt 8
545 .Sh BUGS
546 .Nm Restore
547 can get confused when doing incremental restores from
548 dumps that were made on active file systems.
549 .Pp
550 A level 0 dump must be done after a full restore.
551 Because
552 .Nm restore
553 runs in user code,
554 it has no control over inode allocation;
555 thus a full dump must be done to get a new set of directories
556 reflecting the new inode numbering,
557 even though the content of the files is unchanged.
558 .Pp
559 The temporary files
560 .Pa /tmp/rstdir*
561 and
562 .Pa /tmp/rstmode*
563 are generated with a unique name based on the date of the dump
564 and the process ID (see
565 .Xr mktemp 3 ),
566 except when
567 .Fl r
568 or
569 .Fl R
570 is used.
571 Because
572 .Fl R
573 allows you to restart a
574 .Fl r
575 operation that may have been interrupted, the temporary files should
576 be the same across different processes.
577 In all other cases, the files are unique because it is possible to
578 have two different dumps started at the same time, and separate
579 operations shouldn't conflict with each other.
580 .Pp
581 To do a network restore, you have to run restore as root or use
582 a remote shell replacement (see RSH variable). This is due
583 to the previous security history of dump and restore. (restore is
584 written to be setuid root, but we are not certain all bugs are gone
585 from the restore code - run setuid at your own risk.)
586 .Sh AUTHOR
587 The
588 .Nm dump/restore
589 backup suit was ported to Linux's Second Extended File System
590 by Remy Card <card@Linux.EU.Org>. He maintained the initial versions
591 of dump (up and including 0.4b4, released in january 1997).
592 .Pp
593 Starting with 0.4b5, the new maintainer is Stelian Pop
594 .br
595 <pop@noos.fr>.
596 .Sh AVAILABILITY
597 The
598 .Nm dump/restore
599 backup suit is available from
600 .br
601 http://dump.sourceforge.net
602 .Sh HISTORY
603 The
604 .Nm restore
605 command appeared in
606 .Bx 4.2 .