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1 | .\" Copyright (c) 1980, 1991, 1993 |
2 | .\" Regents of the University of California. | |
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8 | .\" 1. Redistributions of source code must retain the above copyright | |
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12 | .\" documentation and/or other materials provided with the distribution. | |
e1abc9ce | 13 | .\" 3. Neither the name of the University nor the names of its contributors |
1227625a SP |
14 | .\" may be used to endorse or promote products derived from this software |
15 | .\" without specific prior written permission. | |
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17 | .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
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aeb0b047 | 29 | .\" $Id: dump.8.in,v 1.62 2009/06/18 09:40:03 stelian Exp $ |
1227625a | 30 | .\" |
153f9a83 SP |
31 | .TH DUMP 8 "version __VERSION__ of __DATE__" BSD "System management commands" |
32 | .SH NAME | |
33 | dump \- ext2/3 filesystem backup | |
34 | .SH SYNOPSIS | |
35 | .B dump | |
28ba5cae SP |
36 | [\fB\-\fIlevel#\fR] |
37 | [\fB\-ackMnqSuv] | |
153f9a83 SP |
38 | [\fB\-A \fIfile\fR] |
39 | [\fB\-B \fIrecords\fR] | |
40 | [\fB\-b \fIblocksize\fR] | |
41 | [\fB\-d \fIdensity\fR] | |
c92d83ae | 42 | [\fB\-D \fIfile\fR] |
153f9a83 SP |
43 | [\fB\-e \fIinode numbers\fR] |
44 | [\fB\-E \fIfile\fR] | |
45 | [\fB\-f \fIfile\fR] | |
46 | [\fB\-F \fIscript\fR] | |
47 | [\fB\-h \fIlevel\fR] | |
48 | [\fB\-I \fInr errors\fR] | |
49 | [\fB\-j\fIcompression level\fR] | |
50 | [\fB\-L \fIlabel\fR] | |
51 | [\fB\-Q \fIfile\fR] | |
52 | [\fB\-s \fIfeet\fR] | |
53 | [\fB\-T \fIdate\fR] | |
206f768c | 54 | [\fB\-y\fR] |
153f9a83 SP |
55 | [\fB\-z\fIcompression level\fR] |
56 | .I files-to-dump | |
57 | .PP | |
58 | .B dump | |
59 | [\fB\-W \fR| \fB\-w\fR] | |
153f9a83 SP |
60 | .SH DESCRIPTION |
61 | .B Dump | |
62 | examines files on an ext2/3 filesystem and determines which files need to be | |
63 | backed up. These files are copied to the given disk, tape or other storage | |
64 | medium for safe keeping (see the | |
65 | .B \-f | |
66 | option below for doing remote backups). A dump that is larger than the output | |
67 | medium is broken into multiple volumes. On most media the size is determined by | |
68 | writing until an end-of-media indication is returned. | |
69 | .PP | |
70 | On media that cannot reliably return an end-of-media indication (such as some | |
71 | cartridge tape drives), each volume is of a fixed size; the actual size is | |
72 | determined by specifying cartridge media, or via the tape size, density and/or | |
73 | block count options below. By default, the same output file name is used for | |
74 | each volume after prompting the operator to change media. | |
75 | .PP | |
76 | .I files-to-dump | |
77 | is either a mountpoint of a filesystem or a list of files and directories to be | |
78 | backed up as a subset of a filesystem. In the former case, either the path to a | |
79 | mounted filesystem or the device of an unmounted filesystem can be used. In the | |
80 | latter case, certain restrictions are placed on the backup: | |
81 | .B \-u | |
a94ecd11 | 82 | is not allowed, the only dump level that is supported is |
153f9a83 | 83 | .B 0 |
a94ecd11 | 84 | and all the files and directories must reside on the same filesystem. |
153f9a83 | 85 | .SH OPTIONS |
1227625a | 86 | The following options are supported by |
153f9a83 SP |
87 | .B dump: |
88 | .TP | |
28ba5cae | 89 | .BI \-level# |
2ec40843 SP |
90 | The dump level (any integer). A level 0, full backup, specified by |
91 | .B \-0 | |
92 | guarantees the entire file system is copied (but see also the | |
153f9a83 SP |
93 | .B \-h |
94 | option below). A level number above 0, incremental backup, tells | |
95 | .B dump | |
ddd2ef55 | 96 | to |
153f9a83 | 97 | copy all files new or modified since the last dump of a lower level. The |
f39dae99 | 98 | default level is 0. Historically only levels 0 to 9 were usable in |
28ba5cae | 99 | dump, this version is able to understand any integer as a dump level. |
153f9a83 SP |
100 | .TP |
101 | .BI \-a | |
102 | \*(lqauto-size\*(rq. Bypass all tape length calculations, and write until an | |
103 | end-of-media indication is returned. This works best for most modern tape | |
104 | drives, and is the default. Use of this option is particularly recommended when | |
105 | appending to an existing tape, or using a tape drive with hardware compression | |
4f4eee3d | 106 | (where you can never be sure about the compression ratio). |
153f9a83 SP |
107 | .TP |
108 | .BI \-A " archive_file" | |
109 | Archive a dump table-of-contents in the specified | |
110 | .I archive_file | |
e51470bf | 111 | to be used by |
153f9a83 | 112 | .BR restore (8) |
e51470bf | 113 | to determine whether a file is in the dump file that is being restored. |
153f9a83 SP |
114 | .TP |
115 | .BI \-b " blocksize" | |
8ad151aa SP |
116 | The number of kilobytes per dump record. The default blocksize is 10, |
117 | unless the | |
118 | .B \-d | |
119 | option has been used to specify a tape density of 6250BPI or more, | |
120 | in which case the default blocksize is 32. Th maximal value is 1024. | |
876861d2 SP |
121 | Note however that, since the IO system slices all requests into chunks |
122 | of | |
153f9a83 | 123 | .B MAXBSIZE |
876861d2 SP |
124 | (which can be as low as 64kB), you can experience problems with |
125 | .BR dump (8) | |
126 | and | |
127 | .BR restore (8) | |
128 | when using a higher value, depending on your kernel and/or libC versions. | |
153f9a83 SP |
129 | .TP |
130 | .BI \-B " records" | |
27305a35 | 131 | The number of 1 kB blocks per volume. Not normally required, as |
153f9a83 | 132 | .B dump |
27305a35 | 133 | can detect end-of-media. When the specified size is reached, |
153f9a83 SP |
134 | .B dump |
135 | waits for you to change the volume. This option overrides the calculation of | |
136 | tape size based on length and density. If compression is on this limits the | |
d435f57f SP |
137 | size of the compressed output per volume. Multiple values may be given |
138 | as a single argument separated by commas. Each value will be used for one | |
139 | dump volume in the order listed; if | |
140 | .B dump | |
141 | creates more volumes than the | |
142 | number of values given, the last value will be used for the remaining | |
143 | volumes. This is useful for filling up already partially filled media | |
144 | (and then continuing with full size volumes on empty media) or mixing media | |
145 | of different sizes. | |
153f9a83 SP |
146 | .TP |
147 | .BI \-c | |
148 | Change the defaults for use with a cartridge tape drive, with a density of 8000 | |
149 | bpi, and a length of 1700 feet. Specifying a cartridge drive overrides the | |
e51470bf | 150 | end-of-media detection. |
153f9a83 SP |
151 | .TP |
152 | .BI \-d " density" | |
153 | Set tape density to | |
154 | .IR density . | |
155 | The default is 1600BPI. Specifying a tape density overrides the end-of-media | |
156 | detection. | |
157 | .TP | |
c92d83ae SP |
158 | .BI \-D " file" |
159 | Set the path name of the file storing the information about the previous | |
160 | full and incremental dumps. The default location is | |
161 | .IR __DUMPDATES__ . | |
162 | .TP | |
153f9a83 | 163 | .BI \-e " inodes" |
20c345aa | 164 | Exclude |
153f9a83 | 165 | .I inodes |
6d732772 | 166 | from the dump. The |
153f9a83 | 167 | .I inodes |
6d732772 | 168 | parameter is a comma separated list of inode numbers (you can use |
153f9a83 | 169 | .BR stat (1) |
20c345aa | 170 | to find the inode number for a file or directory). |
153f9a83 SP |
171 | .TP |
172 | .BI \-E " file" | |
6d732772 | 173 | Read list of inodes to be excluded from the dump from the text file |
153f9a83 | 174 | .IR file . |
6d732772 | 175 | The file |
153f9a83 SP |
176 | .I file |
177 | should be an ordinary file containing inode numbers separated by newlines. | |
178 | .TP | |
179 | .BI \-f " file" | |
1227625a | 180 | Write the backup to |
153f9a83 SP |
181 | .IR file ; |
182 | .I file | |
183 | may be a special device file like | |
184 | .I /dev/st0 | |
1227625a | 185 | (a tape drive), |
153f9a83 SP |
186 | .I /dev/rsd1c |
187 | (a floppy disk drive), an ordinary file, or | |
188 | .I \- | |
189 | (the standard output). Multiple file names may be given as a single argument | |
190 | separated by commas. Each file will be used for one dump volume in the order | |
191 | listed; if the dump requires more volumes than the number of names given, | |
192 | the last file name will used for all remaining volumes after prompting for | |
193 | media changes. If the name of the file is of the form | |
194 | .I host:file | |
1227625a | 195 | or |
153f9a83 SP |
196 | .I user@host:file |
197 | .B dump | |
ae6919a7 SP |
198 | writes to the named file on the remote host (which should already |
199 | exist, dump doesn't create a new remote file) using | |
153f9a83 | 200 | .BR rmt (8). |
b45f51d6 | 201 | The default path name of the remote |
153f9a83 | 202 | .BR rmt (8) |
b45f51d6 | 203 | program is |
153f9a83 | 204 | .IR /etc/rmt ; |
b45f51d6 | 205 | this can be overridden by the environment variable |
153f9a83 SP |
206 | .BR RMT . |
207 | .TP | |
208 | .BI \-F " script" | |
172af402 SP |
209 | Run script at the end of each tape (except for the last one). |
210 | The device name and the current volume number are passed on the | |
211 | command line. The script must return 0 if | |
153f9a83 | 212 | .B dump |
ae81b200 | 213 | should continue without asking the user to change the tape, 1 if |
153f9a83 SP |
214 | .B dump |
215 | should continue but ask the user to change the tape. Any other exit code will | |
216 | cause | |
217 | .B dump | |
218 | to abort. For security reasons, | |
219 | .B dump | |
220 | reverts back to the real user ID and the real group ID before running the | |
221 | script. | |
222 | .TP | |
223 | .BI \-h " level" | |
e51470bf | 224 | Honor the user |
153f9a83 | 225 | .B nodump |
e51470bf | 226 | flag |
153f9a83 | 227 | .B UF_NODUMP |
e51470bf | 228 | only for dumps at or above the given |
153f9a83 SP |
229 | .IR level . |
230 | The default honor level is 1, so that incremental backups omit such files but | |
231 | full backups retain them. | |
232 | .TP | |
233 | .BI \-I " nr errors" | |
b82d31dc | 234 | By default, |
153f9a83 SP |
235 | .B dump |
236 | will ignore the first 32 read errors on the file system before asking for | |
237 | operator intervention. You can change this using this flag to any value. This | |
238 | is useful when running | |
239 | .B dump | |
240 | on an active filesystem where read errors simply indicate an inconsistency | |
241 | between the mapping and dumping passes. | |
3211c85b SP |
242 | .IP |
243 | A value of 0 means that all read errors will be ignored. | |
153f9a83 SP |
244 | .TP |
245 | .BI \-j "compression level" | |
246 | Compress every block to be written on the tape using bzlib library. This option | |
247 | will work only when dumping to a file or pipe or, when dumping to a tape drive, | |
248 | if the tape drive is capable of writing variable length blocks. You will need | |
249 | at least the 0.4b24 version of | |
250 | .B restore | |
251 | in order to extract compressed tapes. Tapes written using compression will not | |
252 | be compatible with the BSD tape format. The (optional) parameter specifies the | |
253 | compression level bzlib will use. The default compression level is 2. If the | |
254 | optional parameter is specified, there should be no white space between the | |
255 | option letter and the parameter. | |
256 | .TP | |
257 | .BI \-k | |
258 | Use Kerberos authentication to talk to remote tape servers. (Only available if | |
259 | this option was enabled when | |
260 | .B dump | |
b45f51d6 | 261 | was compiled.) |
153f9a83 SP |
262 | .TP |
263 | .BI \-L " label" | |
b45f51d6 | 264 | The user-supplied text string |
153f9a83 | 265 | .I label |
b45f51d6 | 266 | is placed into the dump header, where tools like |
153f9a83 | 267 | .BR restore (8) |
b45f51d6 | 268 | and |
153f9a83 SP |
269 | .BR file (8) |
270 | can access it. Note that this label is limited to be at most | |
271 | .B LBLSIZE | |
272 | (currently 16) characters, which must include the terminating \e0. | |
273 | .TP | |
274 | .BI \-m | |
0cedbda5 | 275 | If this flag is specified, |
153f9a83 SP |
276 | .B dump |
277 | will optimise the output for inodes having been changed but not modified since | |
278 | the last dump ('changed' and 'modified' have the meaning defined in | |
279 | .BR stat (2) | |
280 | ). For those inodes, | |
281 | .B dump | |
282 | will save only the metadata, instead of saving the entire inode contents. | |
283 | Inodes which are either directories or have been modified since the last dump | |
284 | are saved in a regular way. Uses of this flag must be consistent, meaning that | |
285 | either every dump in an incremental dump set have the flag, or no one has it. | |
286 | .IP | |
1753ce67 SP |
287 | If you use this option, be aware that many programs that unpack |
288 | files from archives (e.g. tar, rpm, unzip, dpkg) may set files' | |
289 | mtimes to dates in the past. Files installed in this way may not be | |
290 | dumped correctly using "dump -m" if the modified mtime is earlier | |
291 | than the previous level dump. | |
292 | .IP | |
153f9a83 SP |
293 | Tapes written using such 'metadata only' inodes will not be compatible with the |
294 | BSD tape format or older versions of | |
295 | .B restore. | |
296 | .TP | |
297 | .BI \-M | |
dc7cb1e2 | 298 | Enable the multi-volume feature. The name specified with |
153f9a83 | 299 | .B f |
dc7cb1e2 | 300 | is treated as a prefix and |
153f9a83 SP |
301 | .B dump |
302 | writes in sequence to | |
303 | .I <prefix>001, <prefix>002 | |
304 | etc. This can be useful when dumping to files on an ext2 partition, in order to | |
305 | bypass the 2GB file size limitation. | |
306 | .TP | |
307 | .BI \-n | |
1227625a | 308 | Whenever |
153f9a83 SP |
309 | .B dump |
310 | requires operator attention, notify all operators in the group | |
311 | .B operator | |
1227625a | 312 | by means similar to a |
153f9a83 SP |
313 | .BR wall (1). |
314 | .TP | |
315 | .BI \-q | |
e084ba00 | 316 | Make |
153f9a83 SP |
317 | .B dump |
318 | abort immediately whenever operator attention is required, without prompting in | |
319 | case of write errors, tape changes etc. | |
320 | .TP | |
321 | .BI \-Q " file" | |
322 | Enable the Quick File Access support. Tape positions for each inode are stored | |
323 | into the file | |
324 | .I file | |
325 | which is used by | |
326 | .B restore | |
327 | (if called with parameter | |
328 | .B \-Q | |
329 | and the filename) to directly position the tape at the file | |
330 | .B restore | |
331 | is currently working on. This saves hours when restoring single files from | |
332 | large backups, saves the tapes and the drive's head. | |
333 | .IP | |
334 | It is recommended to set up the st driver to return logical tape positions | |
335 | rather than physical before calling | |
336 | .B dump/restore | |
337 | with parameter | |
338 | .BR \-Q . | |
339 | Since not all tape devices support physical tape positions those tape devices | |
340 | return an error during | |
341 | .B dump/restore | |
342 | when the st driver is set to the default physical setting. Please see the | |
343 | .BR st (4) | |
344 | man page, option | |
345 | .B MTSETDRVBUFFER | |
346 | , or the | |
347 | .BR mt (1) | |
348 | man page, on how to set the driver to return logical tape positions. | |
349 | .IP | |
350 | Before calling | |
351 | .B restore | |
352 | with parameter | |
353 | .BR \-Q , | |
354 | always make sure the st driver is set to return the same type of tape position | |
355 | used during the call to | |
356 | .BR dump . | |
357 | Otherwise | |
358 | .B restore | |
359 | may be confused. | |
360 | .IP | |
361 | This option can be used when dumping to local tapes (see above) or to local | |
362 | files. | |
363 | .TP | |
364 | .BI \-s " feet" | |
365 | Attempt to calculate the amount of tape needed at a particular density. If this | |
366 | amount is exceeded, | |
367 | .B dump | |
368 | prompts for a new tape. It is recommended to be a bit conservative on this | |
369 | option. The default tape length is 2300 feet. Specifying the tape size | |
4f4eee3d | 370 | overrides end-of-media detection. |
153f9a83 SP |
371 | .TP |
372 | .BI \-S | |
373 | Size estimate. Determine the amount of space that is needed to perform the dump | |
374 | without actually doing it, and display the estimated number of bytes it will | |
375 | take. This is useful with incremental dumps to determine how many volumes of | |
376 | media will be needed. | |
377 | .TP | |
378 | .BI \-T " date" | |
379 | Use the specified date as the starting time for the dump instead of the time | |
380 | determined from looking in | |
381 | .I __DUMPDATES__ . | |
ddd2ef55 | 382 | The format of |
153f9a83 | 383 | .I date |
ddd2ef55 | 384 | is the same as that of |
3458b64d SP |
385 | .BR ctime (3) |
386 | followed by an rfc822 timezone specification: either a plus or minus sign | |
387 | followed by two digits for the number of hours and two digits for the minutes. | |
388 | For example, -0800 for eight hours west of Greenwich or +0230 for two hours | |
389 | and a half east of Greenwich. This timezone offset takes into account | |
390 | daylight savings time (if applicable to the timezone): UTC offsets | |
391 | when daylight savings time is in effect will be different than offsets | |
392 | when daylight savings time is not in effect. For backward | |
393 | compatibility, if no timezone is specified, a local time is assumed. | |
153f9a83 SP |
394 | This option is useful for automated dump scripts that wish to dump over a |
395 | specific period of time. The | |
396 | .B \-T | |
1227625a | 397 | option is mutually exclusive from the |
153f9a83 | 398 | .B \-u |
1227625a | 399 | option. |
153f9a83 SP |
400 | .TP |
401 | .BI \-u | |
1227625a | 402 | Update the file |
153f9a83 SP |
403 | .I __DUMPDATES__ |
404 | after a successful dump. The format of | |
405 | .I __DUMPDATES__ | |
406 | is readable by people, consisting of one free format record per line: | |
407 | filesystem name, increment level and | |
408 | .BR ctime (3) | |
3458b64d SP |
409 | format dump date followed by a rfc822 timezone specification (see the |
410 | .B \-u | |
411 | option for details). If no timezone offset is specified, times are interpreted | |
412 | as local. Whenever the file is written, all dates in the file are converted | |
413 | to the local time zone, without changing the UTC times. There | |
414 | may be only one entry per filesystem at each level. The file | |
153f9a83 SP |
415 | .I __DUMPDATES__ |
416 | may be edited to change any of the fields, if necessary. | |
417 | .TP | |
418 | .BI \-v | |
fceb4f25 | 419 | The |
153f9a83 | 420 | .B \-v |
fceb4f25 | 421 | (verbose) makes |
153f9a83 | 422 | .B dump |
fceb4f25 | 423 | to print extra information which could be helpful in debug sessions. |
153f9a83 SP |
424 | .TP |
425 | .BI \-W | |
426 | .B Dump | |
427 | tells the operator what file systems need to be dumped. This information is | |
428 | gleaned from the files | |
429 | .I __DUMPDATES__ | |
1227625a | 430 | and |
153f9a83 | 431 | .IR /etc/fstab . |
1227625a | 432 | The |
153f9a83 | 433 | .B \-W |
1227625a | 434 | option causes |
153f9a83 | 435 | .B dump |
51b01afe | 436 | to print out, for all file systems in |
153f9a83 | 437 | .I __DUMPDATES__ , |
aeb0b047 | 438 | and recognized file systems in |
a8a6a503 SP |
439 | .I /etc/mtab |
440 | and | |
153f9a83 SP |
441 | .IR /etc/fstab . |
442 | the most recent dump date and level, and highlights those that should be | |
443 | dumped. If the | |
444 | .B \-W | |
1227625a | 445 | option is set, all other options are ignored, and |
153f9a83 | 446 | .B dump |
1227625a | 447 | exits immediately. |
153f9a83 SP |
448 | .TP |
449 | .BI \-w | |
ddd2ef55 | 450 | Is like |
153f9a83 | 451 | .BR \-W , |
51b01afe | 452 | but prints only recognized filesystems in |
a8a6a503 SP |
453 | .I /etc/mtab |
454 | and | |
153f9a83 | 455 | .I /etc/fstab |
51b01afe | 456 | which need to be dumped. |
153f9a83 | 457 | .TP |
206f768c SP |
458 | .BI \-y |
459 | Compress every block to be written to the tape using the lzo library. | |
460 | This doesn't compress as well as the zlib library but it's much faster. | |
461 | This option will work only when dumping to a file or pipe or, when dumping to | |
462 | a tape drive, if the tape drive is capable of writing variable length blocks. | |
463 | You will need at least the 0.4b34 version of | |
464 | .B restore | |
465 | in order to extract compressed tapes. Tapes written using compression will not | |
466 | be compatible with the BSD tape format. | |
467 | .TP | |
153f9a83 SP |
468 | .BI \-z "compression level" |
469 | Compress every block to be written on the tape using zlib library. This option | |
470 | will work only when dumping to a file or pipe or, when dumping to a tape drive, | |
471 | if the tape drive is capable of writing variable length blocks. You will need | |
472 | at least the 0.4b22 version of | |
473 | .B restore | |
474 | in order to extract compressed tapes. Tapes written using compression will not | |
475 | be compatible with the BSD tape format. The (optional) parameter specifies the | |
476 | compression level zlib will use. The default compression level is 2. If the | |
477 | optional parameter is specified, there should be no white space between the | |
478 | option letter and the parameter. | |
479 | .PP | |
480 | .B Dump | |
481 | requires operator intervention on these conditions: end of tape, end of dump, | |
482 | tape write error, tape open error or disk read error (if there is more than a | |
483 | threshold of nr errors). In addition to alerting all operators implied by the | |
484 | .B \-n | |
1227625a | 485 | key, |
153f9a83 SP |
486 | .B dump |
487 | interacts with the operator on dump's control terminal at times when | |
488 | .B dump | |
489 | can no longer proceed, or if something is grossly wrong. All questions | |
490 | .B dump | |
1227625a | 491 | poses |
153f9a83 SP |
492 | .I must |
493 | be answered by typing \*(lqyes\*(rq or \*(lqno\*(rq, appropriately. | |
494 | .PP | |
1227625a | 495 | Since making a dump involves a lot of time and effort for full dumps, |
153f9a83 SP |
496 | .B dump |
497 | checkpoints itself at the start of each tape volume. If writing that volume | |
498 | fails for some reason, | |
499 | .B dump | |
500 | will, with operator permission, restart itself from the checkpoint after the | |
501 | old tape has been rewound and removed, and a new tape has been mounted. | |
502 | .PP | |
503 | .B Dump | |
504 | tells the operator what is going on at periodic intervals, including usually | |
505 | low estimates of the number of blocks to write, the number of tapes it will | |
506 | take, the time to completion, and the time to the tape change. The output is | |
507 | verbose, so that others know that the terminal controlling | |
508 | .B dump | |
509 | is busy, and will be for some time. | |
510 | .PP | |
511 | In the event of a catastrophic disk event, the time required to restore all the | |
512 | necessary backup tapes or files to disk can be kept to a minimum by staggering | |
513 | the incremental dumps. An efficient method of staggering incremental dumps to | |
514 | minimize the number of tapes follows: | |
515 | .IP \(em | |
1227625a | 516 | Always start with a level 0 backup, for example: |
153f9a83 SP |
517 | .RS 14 |
518 | .B /sbin/dump -0u -f /dev/st0 /usr/src | |
519 | .RE | |
520 | .IP | |
1227625a SP |
521 | This should be done at set intervals, say once a month or once every two months, |
522 | and on a set of fresh tapes that is saved forever. | |
153f9a83 | 523 | .IP \(em |
34ec103e SP |
524 | After a level 0, dumps of active file systems are taken on a daily basis, |
525 | with this sequence of dump levels: | |
153f9a83 SP |
526 | .RS 14 |
527 | .B 3 2 5 4 7 6 9 8 9 9 ... | |
528 | .RE | |
529 | .IP | |
530 | For the daily dumps, it should be possible to use a fixed number of tapes for | |
531 | each day, used on a weekly basis. Each week, a level 1 dump is taken, and the | |
532 | daily Hanoi sequence repeats beginning with 3. For weekly dumps, another fixed | |
533 | set of tapes per dumped file system is used, also on a cyclical basis. | |
534 | .PP | |
535 | After several months or so, the daily and weekly tapes should get rotated out | |
536 | of the dump cycle and fresh tapes brought in. | |
b79d20f1 | 537 | .PP |
34ec103e SP |
538 | Another backup strategy is the Tower of Hanoi sequence, which reuses |
539 | older tapes in a way that for newer dates the available restore points | |
540 | are more frequent, then for older dates (see | |
541 | http://en.wikipedia.org/wiki/Backup_rotation_scheme for additional | |
542 | information). | |
543 | .PP | |
b79d20f1 SP |
544 | (The 4.3BSD option syntax is implemented for backward compatibility but is not |
545 | documented here.) | |
153f9a83 SP |
546 | .SH ENVIRONMENT |
547 | .TP | |
548 | .B TAPE | |
549 | If no | |
550 | .B \-f | |
551 | option was specified, | |
552 | .B dump | |
b45f51d6 | 553 | will use the device specified via |
153f9a83 | 554 | .B TAPE |
b45f51d6 | 555 | as the dump device. |
153f9a83 | 556 | .B TAPE |
b45f51d6 | 557 | may be of the form |
153f9a83 SP |
558 | .IR tapename , |
559 | .IR host:tapename , | |
b45f51d6 | 560 | or |
153f9a83 SP |
561 | .IR user@host:tapename . |
562 | .TP | |
563 | .B RMT | |
b45f51d6 | 564 | The environment variable |
153f9a83 | 565 | .B RMT |
b45f51d6 | 566 | will be used to determine the pathname of the remote |
153f9a83 | 567 | .BR rmt (8) |
b45f51d6 | 568 | program. |
153f9a83 SP |
569 | .TP |
570 | .B RSH | |
571 | .B Dump | |
572 | uses the contents of this variable to determine the name of the remote shell | |
573 | command to use when doing remote backups (rsh, ssh etc.). If this variable is | |
574 | not set, | |
575 | .BR rcmd (3) | |
0c62667d | 576 | will be used, but only root will be able to do remote backups. |
153f9a83 SP |
577 | .SH FILES |
578 | .TP | |
579 | .I /dev/st0 | |
1227625a | 580 | default tape unit to dump to |
153f9a83 SP |
581 | .TP |
582 | .I __DUMPDATES__ | |
1227625a | 583 | dump date records |
153f9a83 SP |
584 | .TP |
585 | .I /etc/fstab | |
1227625a | 586 | dump table: file systems and frequency |
153f9a83 | 587 | .TP |
a8a6a503 SP |
588 | .I /etc/mtab |
589 | dump table: mounted file systems | |
590 | .TP | |
153f9a83 | 591 | .I /etc/group |
1227625a | 592 | to find group |
153f9a83 SP |
593 | .I operator |
594 | .SH SEE ALSO | |
595 | .BR fstab (5), | |
596 | .BR restore (8), | |
597 | .BR rmt (8) | |
598 | .SH DIAGNOSTICS | |
1227625a | 599 | Many, and verbose. |
3458b64d SP |
600 | .SH COMPATIBILITY |
601 | The format of the | |
602 | .I __DUMPDATES__ | |
603 | file has changed in release 0.4b34, however, the file will be read | |
604 | correctly with either pre-0.4b34 or 0.4b34 and later versions of | |
605 | .B dump | |
606 | provided that the machine on which | |
607 | .B dump | |
aeb0b047 | 608 | is run did not change timezones (which should be a fairly rare occurrence). |
153f9a83 SP |
609 | .SH EXIT STATUS |
610 | .B Dump | |
611 | exits with zero status on success. Startup errors are indicated with an exit | |
612 | code of 1; abnormal termination is indicated with an exit code of 3. | |
613 | .SH BUGS | |
614 | It might be considered a bug that this version of dump can only handle ext2/3 | |
ddd2ef55 | 615 | filesystems. Specifically, it does not work with FAT filesystems. |
153f9a83 SP |
616 | .PP |
617 | Fewer than 32 read errors (change this with | |
618 | .BR \-I ) | |
619 | on the filesystem are ignored. If noticing read errors is important, the output | |
620 | from dump can be parsed to look for lines that contain the text 'read error'. | |
621 | .PP | |
aa1b1e7f | 622 | When a read error occurs, |
153f9a83 | 623 | .B dump |
aa1b1e7f | 624 | prints out the corresponding physical disk block and sector number and the |
aeb0b047 | 625 | ext2/3 logical block number. It doesn't print out the corresponding file name or |
153f9a83 SP |
626 | even the inode number. The user has to use |
627 | .BR debugfs (8), | |
aa1b1e7f | 628 | commands |
153f9a83 | 629 | .B ncheck |
aa1b1e7f | 630 | and |
153f9a83 | 631 | .B icheck |
aa1b1e7f | 632 | to translate the |
153f9a83 SP |
633 | .B ext2blk |
634 | number printed out by | |
635 | .B dump | |
636 | into an inode number, then into a file name. | |
637 | .PP | |
638 | Each reel requires a new process, so parent processes for reels already written | |
639 | just hang around until the entire tape is written. | |
640 | .PP | |
e7850aac | 641 | The estimated number of tapes is not correct if compression is on. |
153f9a83 | 642 | .PP |
1227625a | 643 | It would be nice if |
153f9a83 SP |
644 | .B dump |
645 | knew about the dump sequence, kept track of the tapes scribbled on, told the | |
646 | operator which tape to mount when, and provided more assistance for the | |
647 | operator running | |
648 | .BR restore . | |
649 | .PP | |
650 | .B Dump | |
651 | cannot do remote backups without being run as root, due to its security history. | |
652 | Presently, it works if you set it setuid (like it used to be), but this might | |
653 | constitute a security risk. Note that you can set | |
654 | .B RSH | |
655 | to use a remote shell program instead. | |
656 | .SH AUTHOR | |
8d4197bb | 657 | The |
153f9a83 SP |
658 | .B dump/restore |
659 | backup suite was ported to Linux's Second Extended File System by Remy Card | |
660 | <card@Linux.EU.Org>. He maintained the initial versions of | |
661 | .B dump | |
aeb0b047 | 662 | (up and including 0.4b4, released in January 1997). |
153f9a83 SP |
663 | .PP |
664 | Starting with 0.4b5, the new maintainer is Stelian Pop <stelian@popies.net>. | |
665 | .SH AVAILABILITY | |
8d4197bb | 666 | The |
153f9a83 SP |
667 | .B dump/restore |
668 | backup suite is available from <http://dump.sourceforge.net> | |
669 | .SH HISTORY | |
1227625a | 670 | A |
153f9a83 | 671 | .B dump |
b45f51d6 | 672 | command appeared in |
153f9a83 | 673 | .B Version 6 AT&T UNIX. |