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1227625a SP |
1 | .\" Copyright (c) 1980, 1991, 1993 |
2 | .\" Regents of the University of California. | |
3 | .\" All rights reserved. | |
4 | .\" | |
5 | .\" Redistribution and use in source and binary forms, with or without | |
6 | .\" modification, are permitted provided that the following conditions | |
7 | .\" are met: | |
8 | .\" 1. Redistributions of source code must retain the above copyright | |
9 | .\" notice, this list of conditions and the following disclaimer. | |
10 | .\" 2. Redistributions in binary form must reproduce the above copyright | |
11 | .\" notice, this list of conditions and the following disclaimer in the | |
12 | .\" documentation and/or other materials provided with the distribution. | |
13 | .\" 3. All advertising materials mentioning features or use of this software | |
ddd2ef55 | 14 | .\" must display the following acknowledgement: |
1227625a SP |
15 | .\" This product includes software developed by the University of |
16 | .\" California, Berkeley and its contributors. | |
17 | .\" 4. Neither the name of the University nor the names of its contributors | |
18 | .\" may be used to endorse or promote products derived from this software | |
19 | .\" without specific prior written permission. | |
20 | .\" | |
21 | .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
22 | .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
23 | .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
24 | .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
25 | .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
26 | .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
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28 | .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
29 | .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
30 | .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
31 | .\" SUCH DAMAGE. | |
32 | .\" | |
109e9e1d | 33 | .\" $Id: dump.8.in,v 1.19 2000/12/04 15:43:16 stelian Exp $ |
1227625a | 34 | .\" |
8d4197bb | 35 | .Dd __DATE__ |
1227625a | 36 | .Dt DUMP 8 |
df9ae507 | 37 | .Os "dump __VERSION__" |
1227625a SP |
38 | .Sh NAME |
39 | .Nm dump | |
ddd2ef55 | 40 | .Nd ext2 filesystem backup |
1227625a SP |
41 | .Sh SYNOPSIS |
42 | .Nm dump | |
dc7cb1e2 | 43 | .Op Fl 0123456789ackMnSu |
1227625a SP |
44 | .Op Fl B Ar records |
45 | .Op Fl b Ar blocksize | |
46 | .Op Fl d Ar density | |
0d7af9c5 | 47 | .Op Fl e Ar inode number |
1227625a | 48 | .Op Fl f Ar file |
0d7af9c5 | 49 | .Op Fl F Ar script |
1227625a | 50 | .Op Fl h Ar level |
b45f51d6 | 51 | .Op Fl L Ar label |
1227625a SP |
52 | .Op Fl s Ar feet |
53 | .Op Fl T Ar date | |
79e31865 | 54 | .Ar file-to-dump |
1227625a SP |
55 | .Nm dump |
56 | .Op Fl W Li \&| Fl w | |
57 | .Pp | |
8d4197bb | 58 | .in |
1227625a SP |
59 | (The |
60 | .Bx 4.3 | |
ddd2ef55 | 61 | option syntax is implemented for backward compatibility but |
1227625a SP |
62 | is not documented here.) |
63 | .Sh DESCRIPTION | |
64 | .Nm Dump | |
65 | examines files | |
ddd2ef55 | 66 | on an ext2 filesystem |
1227625a SP |
67 | and determines which files |
68 | need to be backed up. These files | |
69 | are copied to the given disk, tape or other | |
70 | storage medium for safe keeping (see the | |
71 | .Fl f | |
72 | option below for doing remote backups). | |
73 | A dump that is larger than the output medium is broken into | |
74 | multiple volumes. | |
75 | On most media the size is determined by writing until an | |
4f4eee3d | 76 | end-of-media indication is returned. |
b45f51d6 | 77 | .Pp |
1227625a | 78 | On media that cannot reliably return an end-of-media indication |
4f4eee3d SP |
79 | (such as some cartridge tape drives), each volume is of a fixed size; |
80 | the actual size is determined by specifying cartridge media, or via the | |
81 | tape size, density and/or block count options below. | |
1227625a SP |
82 | By default, the same output file name is used for each volume |
83 | after prompting the operator to change media. | |
84 | .Pp | |
79e31865 SP |
85 | .Ar file-to-dump |
86 | is either a mountpoint of a filesystem | |
87 | or a directory to be backed up as a subset of a filesystem. | |
88 | In the former case, either the path to a mounted filesystem | |
89 | or the device of an unmounted filesystem can be used. | |
90 | In the latter case, certain restrictions are placed on the backup: | |
91 | .Fl u | |
92 | is not allowed and the only dump level that is supported is | |
93 | .Fl 0 . | |
94 | .Pp | |
1227625a | 95 | The following options are supported by |
b45f51d6 | 96 | .Nm Ns : |
1227625a SP |
97 | .Bl -tag -width Ds |
98 | .It Fl 0\-9 | |
99 | Dump levels. | |
100 | A level 0, full backup, | |
101 | guarantees the entire file system is copied | |
102 | (but see also the | |
103 | .Fl h | |
104 | option below). | |
105 | A level number above 0, | |
106 | incremental backup, | |
ddd2ef55 SP |
107 | tells |
108 | .Nm dump | |
109 | to | |
1227625a | 110 | copy all files new or modified since the |
ae58c8da | 111 | last dump of a lower level. |
ddd2ef55 | 112 | The default level is 9. |
1227625a | 113 | .It Fl B Ar records |
b45f51d6 | 114 | The number of 1 KB blocks per volume. |
4f4eee3d SP |
115 | This option overrides the end-of-media detection, and calculation |
116 | of tape size based on length and density. | |
b45f51d6 SP |
117 | .It Fl a |
118 | .Dq auto-size . | |
4f4eee3d SP |
119 | Bypass all tape length calculations, and write |
120 | until an end-of-media indication is returned. This works best | |
121 | for most modern tape drives, and is the default. | |
122 | Use of this option is particularly recommended when appending to an | |
123 | existing tape, or using a tape drive with hardware compression | |
124 | (where you can never be sure about the compression ratio). | |
1227625a SP |
125 | .It Fl b Ar blocksize |
126 | The number of kilobytes per dump record. | |
ddd2ef55 SP |
127 | Since the IO system slices all requests into chunks of MAXBSIZE |
128 | (typically 64KB), it is not possible to use a larger blocksize | |
129 | without having problems later with | |
130 | .Xr restore 8 . | |
131 | Therefore | |
132 | .Nm dump | |
133 | will constrain writes to MAXBSIZE. | |
65bceb9b | 134 | The default blocksize is 10. |
1227625a | 135 | .It Fl c |
b45f51d6 | 136 | Change the defaults for use with a cartridge tape drive, with a density |
4f4eee3d SP |
137 | of 8000 bpi, and a length of 1700 feet. Specifying a cartridge drive |
138 | overrides the end-of-media detection. | |
20c345aa SP |
139 | .It Fl e Ar inode |
140 | Exclude | |
141 | .Ar inode | |
142 | from the dump (you can use | |
143 | .Ar stat | |
144 | to find the inode number for a file or directory). | |
b45f51d6 SP |
145 | .It Fl h Ar level |
146 | Honor the user | |
147 | .Dq nodump | |
148 | flag | |
149 | .Dp Dv UF_NODUMP | |
150 | only for dumps at or above the given | |
151 | .Ar level . | |
152 | The default honor level is 1, | |
153 | so that incremental backups omit such files | |
154 | but full backups retain them. | |
1227625a SP |
155 | .It Fl d Ar density |
156 | Set tape density to | |
157 | .Ar density . | |
4f4eee3d SP |
158 | The default is 1600BPI. Specifying a tape density overrides the |
159 | end-of-media detection. | |
1227625a SP |
160 | .It Fl f Ar file |
161 | Write the backup to | |
162 | .Ar file ; | |
163 | .Ar file | |
164 | may be a special device file | |
165 | like | |
ddd2ef55 | 166 | .Pa /dev/st0 |
1227625a SP |
167 | (a tape drive), |
168 | .Pa /dev/rsd1c | |
b45f51d6 | 169 | (a floppy disk drive), |
1227625a SP |
170 | an ordinary file, |
171 | or | |
172 | .Ql Fl | |
173 | (the standard output). | |
174 | Multiple file names may be given as a single argument separated by commas. | |
175 | Each file will be used for one dump volume in the order listed; | |
176 | if the dump requires more volumes than the number of names given, | |
177 | the last file name will used for all remaining volumes after prompting | |
178 | for media changes. | |
179 | If the name of the file is of the form | |
ddd2ef55 | 180 | .Dq host:file |
1227625a | 181 | or |
ddd2ef55 | 182 | .Dq user@host:file |
b45f51d6 | 183 | .Nm |
1227625a SP |
184 | writes to the named file on the remote host using |
185 | .Xr rmt 8 . | |
b45f51d6 SP |
186 | The default path name of the remote |
187 | .Xr rmt 8 | |
188 | program is | |
189 | .\" rmt path, is the path on the remote host | |
190 | .Pa /etc/rmt ; | |
191 | this can be overridden by the environment variable | |
192 | .Ev RMT . | |
0d7af9c5 | 193 | .It Fl F Ar script |
365a7c7c SP |
194 | Run script at the end of each tape. The device name and the |
195 | current volume number are passed on the command line. | |
196 | The script must return 0 if | |
ae81b200 SP |
197 | .Nm |
198 | should continue without asking the user to change the tape, 1 if | |
199 | .Nm | |
200 | dump should continue but ask the user to change the tape. | |
201 | Any other exit code will cause | |
202 | .Nm | |
203 | to abort. | |
204 | For security reasons, | |
205 | .Nm | |
206 | reverts back to the real user ID and the real group ID before | |
207 | running the script. | |
b45f51d6 SP |
208 | .It Fl k |
209 | Use Kerberos authentication to talk to remote tape servers. (Only | |
210 | available if this option was enabled when | |
211 | .Nm | |
212 | was compiled.) | |
213 | .It Fl L Ar label | |
214 | The user-supplied text string | |
215 | .Ar label | |
216 | is placed into the dump header, where tools like | |
217 | .Xr restore 8 | |
218 | and | |
219 | .Xr file 1 | |
220 | can access it. | |
221 | Note that this label is limited | |
222 | to be at most LBLSIZE (currently 16) characters, which must include | |
223 | the terminating | |
224 | .Ql \e0 . | |
dc7cb1e2 SP |
225 | .It Fl M |
226 | Enable the multi-volume feature. The name specified with | |
227 | .Fl f | |
228 | is treated as a prefix and | |
229 | .Nm | |
230 | writes in sequence to <prefix>001, <prefix>002 etc. This can be | |
231 | useful when dumping to files on an ext2 partition, in order to bypass | |
232 | the 2GB file size limitation. | |
1227625a SP |
233 | .It Fl n |
234 | Whenever | |
b45f51d6 | 235 | .Nm |
1227625a SP |
236 | requires operator attention, |
237 | notify all operators in the group | |
238 | .Dq operator | |
239 | by means similar to a | |
240 | .Xr wall 1 . | |
241 | .It Fl s Ar feet | |
4f4eee3d | 242 | Attempt to calculate the amount of tape needed at a particular density. |
1227625a | 243 | If this amount is exceeded, |
b45f51d6 | 244 | .Nm |
1227625a SP |
245 | prompts for a new tape. |
246 | It is recommended to be a bit conservative on this option. | |
4f4eee3d SP |
247 | The default tape length is 2300 feet. Specifying the tape size |
248 | overrides end-of-media detection. | |
1227625a | 249 | .ne 1i |
144a6db1 SP |
250 | .It Fl S |
251 | Size estimate. Determine the amount of space | |
252 | that is needed to perform the dump without | |
253 | actually doing it, and display the estimated | |
2e682895 | 254 | number of bytes it will take. This is useful |
144a6db1 SP |
255 | with incremental dumps to determine how many |
256 | volumes of media will be needed. | |
1227625a SP |
257 | .It Fl T Ar date |
258 | Use the specified date as the starting time for the dump | |
259 | instead of the time determined from looking in | |
8d4197bb | 260 | .Pa __DUMPDATES__ . |
ddd2ef55 SP |
261 | The format of |
262 | .Ar date | |
263 | is the same as that of | |
1227625a SP |
264 | .Xr ctime 3 . |
265 | This option is useful for automated dump scripts that wish to | |
266 | dump over a specific period of time. | |
267 | The | |
268 | .Fl T | |
269 | option is mutually exclusive from the | |
270 | .Fl u | |
271 | option. | |
272 | .It Fl u | |
273 | Update the file | |
8d4197bb | 274 | .Pa __DUMPDATES__ |
1227625a SP |
275 | after a successful dump. |
276 | The format of | |
8d4197bb | 277 | .Pa __DUMPDATES__ |
1227625a SP |
278 | is readable by people, consisting of one |
279 | free format record per line: | |
280 | filesystem name, | |
281 | increment level | |
282 | and | |
283 | .Xr ctime 3 | |
284 | format dump date. | |
285 | There may be only one entry per filesystem at each level. | |
286 | The file | |
8d4197bb | 287 | .Pa __DUMPDATES__ |
1227625a SP |
288 | may be edited to change any of the fields, |
289 | if necessary. | |
290 | .It Fl W | |
291 | .Nm Dump | |
292 | tells the operator what file systems need to be dumped. | |
293 | This information is gleaned from the files | |
8d4197bb | 294 | .Pa __DUMPDATES__ |
1227625a SP |
295 | and |
296 | .Pa /etc/fstab . | |
297 | The | |
298 | .Fl W | |
299 | option causes | |
b45f51d6 | 300 | .Nm |
51b01afe | 301 | to print out, for all file systems in |
8d4197bb | 302 | .Pa __DUMPDATES__ , |
51b01afe SP |
303 | and regognized file systems in |
304 | .Pa /etc/fstab . | |
1227625a | 305 | the most recent dump date and level, |
51b01afe | 306 | and highlights those that should be dumped. |
1227625a SP |
307 | If the |
308 | .Fl W | |
309 | option is set, all other options are ignored, and | |
b45f51d6 | 310 | .Nm |
1227625a SP |
311 | exits immediately. |
312 | .It Fl w | |
ddd2ef55 SP |
313 | Is like |
314 | .Fl W , | |
51b01afe SP |
315 | but prints only recognized filesystems in |
316 | .Pa /etc/fstab | |
317 | which need to be dumped. | |
1227625a SP |
318 | .El |
319 | .Pp | |
320 | .Nm Dump | |
321 | requires operator intervention on these conditions: | |
322 | end of tape, | |
323 | end of dump, | |
324 | tape write error, | |
325 | tape open error or | |
ddd2ef55 | 326 | disk read error (if there is more than a threshold of 32). |
1227625a SP |
327 | In addition to alerting all operators implied by the |
328 | .Fl n | |
329 | key, | |
b45f51d6 | 330 | .Nm |
1227625a SP |
331 | interacts with the operator on |
332 | .Em dump's | |
333 | control terminal at times when | |
b45f51d6 | 334 | .Nm |
1227625a SP |
335 | can no longer proceed, |
336 | or if something is grossly wrong. | |
337 | All questions | |
b45f51d6 | 338 | .Nm |
1227625a SP |
339 | poses |
340 | .Em must | |
341 | be answered by typing | |
342 | .Dq yes | |
343 | or | |
344 | .Dq no , | |
345 | appropriately. | |
346 | .Pp | |
347 | Since making a dump involves a lot of time and effort for full dumps, | |
b45f51d6 | 348 | .Nm |
1227625a SP |
349 | checkpoints itself at the start of each tape volume. |
350 | If writing that volume fails for some reason, | |
b45f51d6 | 351 | .Nm |
1227625a SP |
352 | will, |
353 | with operator permission, | |
354 | restart itself from the checkpoint | |
355 | after the old tape has been rewound and removed, | |
356 | and a new tape has been mounted. | |
357 | .Pp | |
358 | .Nm Dump | |
359 | tells the operator what is going on at periodic intervals, | |
360 | including usually low estimates of the number of blocks to write, | |
361 | the number of tapes it will take, the time to completion, and | |
362 | the time to the tape change. | |
363 | The output is verbose, | |
364 | so that others know that the terminal | |
365 | controlling | |
b45f51d6 | 366 | .Nm |
1227625a SP |
367 | is busy, |
368 | and will be for some time. | |
369 | .Pp | |
370 | In the event of a catastrophic disk event, the time required | |
371 | to restore all the necessary backup tapes or files to disk | |
372 | can be kept to a minimum by staggering the incremental dumps. | |
373 | An efficient method of staggering incremental dumps | |
374 | to minimize the number of tapes follows: | |
375 | .Bl -bullet -offset indent | |
376 | .It | |
377 | Always start with a level 0 backup, for example: | |
378 | .Bd -literal -offset indent | |
8d4197bb | 379 | /sbin/dump -0u -f /dev/st0 /usr/src |
1227625a SP |
380 | .Ed |
381 | .Pp | |
382 | This should be done at set intervals, say once a month or once every two months, | |
383 | and on a set of fresh tapes that is saved forever. | |
384 | .It | |
385 | After a level 0, dumps of active file | |
386 | systems are taken on a daily basis, | |
387 | using a modified Tower of Hanoi algorithm, | |
388 | with this sequence of dump levels: | |
389 | .Bd -literal -offset indent | |
390 | 3 2 5 4 7 6 9 8 9 9 ... | |
391 | .Ed | |
392 | .Pp | |
393 | For the daily dumps, it should be possible to use a fixed number of tapes | |
394 | for each day, used on a weekly basis. | |
395 | Each week, a level 1 dump is taken, and | |
396 | the daily Hanoi sequence repeats beginning with 3. | |
397 | For weekly dumps, another fixed set of tapes per dumped file system is | |
398 | used, also on a cyclical basis. | |
399 | .El | |
400 | .Pp | |
401 | After several months or so, the daily and weekly tapes should get | |
402 | rotated out of the dump cycle and fresh tapes brought in. | |
b45f51d6 SP |
403 | .Sh ENVIRONMENT |
404 | .Bl -tag -width Fl | |
405 | .It Ev TAPE | |
406 | If no -f option was specified, | |
407 | .Nm | |
408 | will use the device specified via | |
409 | .Ev TAPE | |
410 | as the dump device. | |
411 | .Ev TAPE | |
412 | may be of the form | |
413 | .Qq tapename , | |
414 | .Qq host:tapename , | |
415 | or | |
416 | .Qq user@host:tapename . | |
417 | .It Ev RMT | |
418 | The environment variable | |
419 | .Ev RMT | |
420 | will be used to determine the pathname of the remote | |
421 | .Xr rmt 8 | |
422 | program. | |
0c62667d SP |
423 | .It Ev RSH |
424 | .Nm Dump | |
425 | uses the contents of this variable to determine the name of the | |
426 | remote shell command to use when doing remote backups (rsh, ssh etc.). | |
427 | If this variable is not set, | |
428 | .Xr rcmd 3 | |
429 | will be used, but only root will be able to do remote backups. | |
1227625a | 430 | .Sh FILES |
8d4197bb | 431 | .Bl -tag -width __DUMPDATES__ -compact |
ddd2ef55 | 432 | .It Pa /dev/st0 |
1227625a | 433 | default tape unit to dump to |
8d4197bb | 434 | .It Pa __DUMPDATES__ |
1227625a SP |
435 | dump date records |
436 | .It Pa /etc/fstab | |
437 | dump table: file systems and frequency | |
438 | .It Pa /etc/group | |
439 | to find group | |
440 | .Em operator | |
441 | .El | |
442 | .Sh SEE ALSO | |
b45f51d6 | 443 | .Xr fstab 5 , |
1227625a | 444 | .Xr restore 8 , |
b45f51d6 | 445 | .Xr rmt 8 |
1227625a SP |
446 | .Sh DIAGNOSTICS |
447 | Many, and verbose. | |
448 | .Pp | |
ddd2ef55 SP |
449 | .Nm Dump |
450 | exits with zero status on success. | |
1227625a SP |
451 | Startup errors are indicated with an exit code of 1; |
452 | abnormal termination is indicated with an exit code of 3. | |
453 | .Sh BUGS | |
ddd2ef55 SP |
454 | It might be considered a bug that this version of dump can only handle ext2 |
455 | filesystems. Specifically, it does not work with FAT filesystems. | |
456 | .Pp | |
457 | Fewer than 32 read errors on the filesystem are ignored. If noticing | |
458 | read errors is important, the output from dump can be parsed to look for lines | |
459 | that contain the text 'read error'. | |
1227625a SP |
460 | .Pp |
461 | Each reel requires a new process, so parent processes for | |
462 | reels already written just hang around until the entire tape | |
463 | is written. | |
464 | .Pp | |
1227625a | 465 | It would be nice if |
b45f51d6 | 466 | .Nm |
1227625a SP |
467 | knew about the dump sequence, |
468 | kept track of the tapes scribbled on, | |
469 | told the operator which tape to mount when, | |
470 | and provided more assistance | |
471 | for the operator running | |
472 | .Xr restore . | |
b45f51d6 SP |
473 | .Pp |
474 | .Nm Dump | |
475 | cannot do remote backups without being run as root, due to its | |
0c62667d | 476 | security history. |
b45f51d6 | 477 | Presently, it works if you set it setuid (like it used to be), but this |
0c62667d SP |
478 | might constitute a security risk. Note that you can set RSH to use |
479 | a remote shell program instead. | |
8d4197bb SP |
480 | .Sh AUTHOR |
481 | The | |
482 | .Nm dump/restore | |
483 | backup suit was ported to Linux's Second Extended File System | |
484 | by Remy Card <card@Linux.EU.Org>. He maintained the initial versions | |
485 | of dump (up and including 0.4b4, released in january 1997). | |
486 | .Pp | |
487 | Starting with 0.4b5, the new maintainer is Stelian Pop | |
488 | .br | |
109e9e1d | 489 | <pop@noos.fr>. |
8d4197bb SP |
490 | .Sh AVAILABILITY |
491 | The | |
492 | .Nm dump/restore | |
01fb6bd5 SP |
493 | backup suit is available from |
494 | .br | |
495 | http://dump.sourceforge.net | |
1227625a SP |
496 | .Sh HISTORY |
497 | A | |
b45f51d6 SP |
498 | .Nm |
499 | command appeared in | |
500 | .At v6 . |