3 Prev Part IV. Various Information Next
5 -------------------------------------------------------------------------------
16 XML-conversion;Updates
22 Refer to http://www.amanda.org/docs/faq.html for the current version of this
24 This file contains answers to some questions that are frequently asked in the
25 Amanda mailing lists, specially by new users. Please take a look at this file
26 before posting, this can save us time that could be spent improving Amanda and
28 New entries and modifications are welcome; send them to mailto://amanda-
29 users@amanda.org or mailto://amanda-hackers@amanda.org.
30 You may also want to take a look at the Amanda FAQ-O-Matic http://
31 www.amanda.org/fom-serve/cache/1.html.
34 Why_does_Amanda_fail_to_build_on_my_system?
36 Why_does_amdump_report_that_all_disks_failed?
38 Why_does_amcheck_say_"port_NNN_is_not_secure"?
40 Why_does_amcheck_claim_that_the_tape_is_"not_an_Amanda_tape"?
42 Why_does_amcheck_report_"selfcheck_request_timed_out"?
44 Why_does_amandad.debug_contain_"error_receiving_message"?
46 Why_does_amcheck_say_"access_as_<username>_not_allowed..."?
48 Why_does_amcheck_report_"ip_address_#.#.#.#"_is_not_in_the_ip_list_list_for
51 Why_does_amcheck_say_"cannot_overwrite_active_tape"?
53 Why_does_amcheck_tell_me_"DUMP_program_not_available"?
55 Which_tape_changer_configuration_should_I_use_in_amanda.conf?
57 Where_do_I_get_my_tapetype-definition_from?_Do_I_have_to_run_amtapetype?
59 Should_I_use_software_or_hardware_compression?
61 How_can_I_configure_Amanda_so_that_it_performs_full_backups_on_the_week-end
62 and_incrementals_on_weekdays?
64 What_if_my_tape_unit_uses_expensive_tapes,_and_I_don't_want_to_use_one_tape
65 per_day?_Can't_Amanda_append_to_tapes?
67 How_can_I_configure_Amanda_for_long-term_archiving?
69 Can_I_backup_separate_disks_of_the_same_host_in_different_configurations?
71 Can_Amanda_span_large_filesystems_across_multiple_tapes?
73 What's_the_difference_between_option_"skip-full"_and_"strategy_nofull"?
75 Why_does_amdump_report_"results_missing"?
77 Why_does_amdump_report_"disk_offline"?
79 What_if_amdump_reports_"dumps_way_too_big,_must_skip_incremental_dumps"?
81 amdump_reported_"infofile_update_failed"._What_should_I_do?
83 Why_does_Amanda_sometimes_promote_full_dumps?
85 Why_does_amrecover_report_"no_index_records"_or_"disk_not_found"?
87 Ok,_I'm_done_with_testing_Amanda,_now_I_want_to_put_it_in_production._How_can
88 I_reset_its_databases_so_as_to_start_from_scratch?
90 The_man-page_of_dump_says_that_active_filesystems_may_be_backed_up
91 inconsistently._What_does_Amanda_do_to_prevent_inconsistent_backups?
93 Which_version_of_GNU-tar_should_I_use?
95 What_does_"bumping"_mean?
97 How_do_I_backup_a_Windows_server?
99 How_do_I_tell_my_iptables-based_firewall_to_allow_Amanda_through?
101 How_do_I_get_rid_of_pressing_"q"_to_get_rid_of_a_pager_prompt_when_using
104 Is_there_a_way_to_tell_the_pager_that_my_terminal_has_"y"_lines?
107 Why does Amanda fail to build on my system?
108 One of the most common reasons for compile-time errors is stale information in
109 config.cache, after a build on a different platform using the same build tree.
110 In order to avoid this problem, make sure you don't ever reuse build trees
111 across platforms, or at least run make distclean before running configure on
113 Another common reason for failure, that causes link-time errors, is a problem
114 in libtool that causes it to search for symbols in already-installed amanda
115 libraries, instead of in the just-built ones. This problem is known to affect
116 SunOS 4.1.3 and FreeBSD. You can usually work around it by specifying a
117 different prefix when you configure the new version of Amanda. However, it may
118 not work if the previous version of Amanda was installed in /usr/local and gcc
119 searches this directory by default; in this case, you must either remove the
120 old libraries (which you don't want to do, right? :-) or call configure with
121 the flag --disable-libtool. In this case, Amanda won't create shared
122 libraries, so binaries will be larger, but you may worry about that later.
123 You may also want to take a look at Amanda_2.5.0_-_System-Specific
124 Installation_Notes, as well as to the Amanda Patches Page (http://
125 www.amanda.org/patches/) for other known problems. If everything fails, you
126 should read the manual, but since we don't have one yet, just post a help
127 request to the amanda-users mailing list (mailto://amanda-users@amanda.org),
128 showing the last few lines of the failed build.
129 Why does amdump report that all disks failed?
130 Probably because the Amanda clients are not properly configured. Before you
131 ever run amdump, make sure amcheck succeeds. When it does, so should amdump.
132 Make sure you run amcheck as the same user that is supposed to start amdump,
133 otherwise you may get incorrect results.
134 Why does amcheck say "port NNN is not secure"?
135 Because amcheck, as some other Amanda programs, must be installed as setuid-
136 root. Run make install as "root", or chown all Amanda setuid programs to
137 "root", then chown u+s them again, if chown drops the setuid bit.
138 Why does amcheck claim that the tape is "not an Amanda tape"?
139 Because Amanda requires you to label tapes before it uses them. Run amlabel in
140 order to label a tape.
141 If, even after labeling a tape, amcheck still complains about it, make sure
142 the regular expression specified in amanda.conf matches the label you have
143 specified, and check whether you have configured non-rewinding tape devices
144 for Amanda to use. For example, use /dev/nrst0 instead of /dev/rst0, /dev/rmt/
145 0bn instead of /dev/rmt/0b, or some other system-dependent device name that
146 contains an "n", instead of one that does not. The "n" stands for non-
148 If you have labeled any tapes using the rewiding device configuration, you'll
149 have to label them again.
150 Why does amcheck report "selfcheck request timed out"?
151 This can occur under several different situations. First, make sure this
152 problem is repeatable; if Amanda programs are NFS-auto-mounted, some clients
153 may fail to mount the Amanda binaries in time.
154 If the error is repeatable, log into the client, and check whether the
155 directory /tmp/amanda exists, and a file named amandad.debug exists in there:
156 amandad will create this file whenever it starts. If this file does not exist,
157 amandad is not starting properly, or it lacks permission to create /tmp/
158 amanda/amandad.debug.
159 In the latter case, wipe out /tmp/amanda, and amandad should create it next
160 time it runs. In the former case, check your inetd configuration. Make sure
161 you have added the Amanda services to /etc/services (or the NIS services map),
162 that /etc/inetd.conf was properly configured, and that you have signalled
163 inetd to reread this file (some systems may need rebooting). Check section 2.2
164 from in the Amanda_Installation_Notes for details. Check the inetd man-page
165 for possible differences between the standard format of /etc/inetd.conf and
166 the one in your system.
167 Pay special attention to typos in /etc/inetd.conf; error messages will
168 probably appear in /var/adm/messages or /var/log/messages if you have typed
169 the amandad program name incorrectly. Make sure the same user that you have
170 specified at configure-time (configure --with-user=<USERNAME>) is listed in /
171 etc/inetd.conf. Check whether this user has permission to run amandad, as well
172 as any shared libraries amandad depends upon, by running the specified amandad
173 command by hand, as the Amanda user. It should just time-out after 30 seconds
174 waiting for a UDP packet. If you type anything, it will abort immediately,
175 because it can't read a UDP packet from the keyboard.
176 As soon as you have properly configured /etc/inetd.conf so as to run amandad,
177 you should no longer get the "selfcheck request timed out" message. A nice
178 tool to help make sure inetd is really listening on the amandad port is lsof,
179 available at ftp://vic.cc.purdue.edu/pub/tools/unix/lsof.
180 Why does amandad.debug contain "error receiving message"?
181 One possibility is that you have run amandad from the command line prompt and
182 typed anything instead of waiting for it to time-out: in this case, it will
183 try to read a UDP packet from the keyboard, and this was reported not to work
184 on most keyboards :-). However, if you have run amandad as any user other than
185 the one listed in /etc/inetd.conf, it may have created a /tmp/amanda directory
186 that the Amanda user cannot write to, so you should wipe it out.
187 Another possibility is that the Amanda service was not properly configured as
188 a UDP service; check /etc/services and /etc/inetd.conf.
189 Why does amcheck say "access as <username> not allowed..."?
190 There must be something wrong with .amandahosts configuration (or .rhosts, if
191 you have configured --without-amandahosts).
192 First, if the <username> is not what you expect (i.e., not what you have
193 specified in the --with-user flag, at configure time), check the inetd
194 configuration file: you must have specified the wrong username there.
195 Make sure you specify the names exactly as they appear in the error message
196 after the `@' sign in .amandahosts/.rhosts. You'll need a fully-qualified
197 domain name or not, depending on how your client resolves IP addresses to host
199 Why does amcheck report "ip address #.#.#.#" is not in the ip list list for
201 Check your DNS configuration tables. In order to avoid DNS-spoofing, Amanda
202 double-checks hostname<->IP address mapping. If the IP address the request
203 comes from maps to a hostname, but this hostname does not map back to the
204 incoming IP address, the request is denied.
205 Why does amcheck say "cannot overwrite active tape"?
206 Because, if you configure Amanda to use N tapes, by setting tapecycle to N in
207 amanda.conf, before Amanda overwrites a tape, it must write to at least other
208 N-1 tapes. Of course, Amanda will always refuse to overwrite a tape marked for
209 `noreuse' with amadmin. Furthermore, such tapes are not counted when Amanda
210 computes `N-1' tapes.
211 If, for some reason, you want to tell Amanda to overwrite a particular tape,
212 regardless of its position in the cycle, use amrmtape. This command will
213 remove this tape from the tapelist file, that is used to manage the tape
214 cycle, and will delete information about backups stored in that tape from the
216 Why does amcheck tell me "DUMP program not available"?
217 Because configure could not find dump when it was first run. This is a common
218 problem on Linux hosts, because most Linux distributions do not install dump
220 If you don't have a DUMP program installed, install it, remove config.cache,
221 run configure again and rebuild Amanda. While configure is running, make sure
222 it can find the installed DUMP program. If it cannot, you may have to set the
223 environment variables DUMP and RESTORE by hand, before running configure.
224 If you can't or don't want to install DUMP, you may use GNU tar, but make sure
225 it as release 1.12 or newer; release 1.11.8 may work, but estimates will be
227 Which tape changer configuration should I use in amanda.conf?
228 If you only have one tape unit, you have two choices:
230 i. Don't use a tape changer at all, i.e., set runtapes to 1, set tapedev to
231 the non-rewinding device corresponding to the tape unit, and comment out
232 tpchanger, changerfile and changerdev
233 ii. Set up chg-manual, so that you can change tapes manually. If you select
234 chg-manual, you will not be able to start amdump as a cron job, and you
235 should always run amflush -f, because chg-manual will ask you to press
236 return in the terminal where you started the controlling program.
238 If you have several tape units, which you want to use to emulate a tape
239 changer, you want chg-multi. Even if you do own a real tape changer, that
240 operates based on ejecting a tape or such, chg-multi may be useful.
241 Actual tape changers usually require specialized changer programs, such as
242 mtx, chio or specific system calls. The availability of these programs is much
243 more dependent on the operating system you're running than on the particular
244 tape changer hardware you have.
245 mtx, for example, is available for several platforms. However, even if you
246 find it for your platform, beware that there exist several different programs
247 named mtx, that require different command line arguments, and print different
248 output, and Amanda's chg-mtx does not support them all. You may have to edit
249 the script, which shouldn't be hard to do.
250 In section BUILT-IN TAPE CHANGERS of Amanda_Tape_Changer_Support you will find
251 details about the tape changer interfacing programs provided with Amanda, that
252 can interact with common tape changer programs and with tape changer-related
253 system calls provided by some operating system. If none of them matches your
254 needs, you may have to develop your own tape changer interface script.
255 Before posting a question to the Amanda mailing lists, *please* search the
256 archives, and try to obtain as much information about driving your tape
257 changer hardware from the vendor of the changer hardware and of the operating
258 system, rather than from the Amanda mailing lists. We usually don't have much
259 to say about tape changer units, and several questions about them remain
261 Anyway, if you decide to post a question, make sure you specify both the tape
262 changer hardware *and* the OS/platform that is going to interface with it.
264 Where do I get my tapetype-definition from? Do I have to run amtapetype?
265 It is not mandatory to run amtapetype at installation-time. It is very likely
266 that your tapedrive or -changer is one of the devices that are already covered
267 by one of the existing tapetype-definitions.
268 You may find tapetype-definitions in the example amanda.conf, in the
269 mailinglist-archives of the amanda-users-mailinglist at http://
270 marc.theaimsgroup.com/?l=amanda-users or in the Amanda-FAQ-O-Matic at http://
271 www.amanda.org/fom-serve/cache/1.html.
272 Reasons to run amtapetype for your device:
274 * You want to generate your own tapetype-definition because you can't find any
275 suitable tapetype-definition for your device.
276 * You want to determine the performance of your device.
277 * You want to determine if your device has hardware-compression enabled.
279 If you decide to run amtapetype, please refer to the chapter Tapetypes and the
280 manpage amtapetype(8).
281 Should I use software or hardware compression?
282 When you enable software compression, you drastically reduce the compression
283 that might be achieved by hardware. In fact, tape drives will usually use
284 *more* tape if you tell them to try to further compress already compressed
286 Thus, you must choose whether you're going to use software or hardware
287 compression; don't ever enable both unless you want to waste tape space.
288 Since Amanda prefers to have complete information about tape sizes and
289 compression rates, it can do a better job if you use software compression.
290 However, if you can't afford the extra CPU usage, Amanda can live with the
291 unpredictability of hardware compression, but you'll have to be very
292 conservative about the specified tape size, specially if there are filesystems
293 that contain mostly uncompressible data.
294 You might want to run amtapetype to determine if you have hardware-compression
295 enabled for your tape-drive.
296 How can I configure Amanda so that it performs full backups on the week-end
297 and incrementals on weekdays?
298 You can't. Amanda doesn't work this way. You just have to tell Amanda how many
299 tapes you have (tapecycle), and how often you want it to perform full backups
300 of each filesystem (dumpcycle). If you don't run it once a daily (including
301 Saturdays and Sundays :-), you'll also want to tell Amanda how many times
302 you'll run it per dumpcycle (runspercycle). It will spread full backups along
303 the dumpcycle, so you won't have any full-only or incremental-only runs.
304 Please also refer to "the friday-tape-question" in Collection_of_the_top_ten
305 Amanda_questions._And_answers..
306 What if my tape unit uses expensive tapes, and I don't want to use one tape
307 per day? Can't Amanda append to tapes?
308 It can't, and this is good. Tape drives and OS drivers are (in)famous for
309 rewinding tapes at unexpected times, without telling the program that's
310 writing to them. If you have a month's worth of backups in that tape, you
311 really don't want them to be overwritten, so Amanda has taken the safe
312 approach of requiring tapes to be written from the beginning on every run.
313 This can be wasteful, specially if you have a small amount of data to back up,
314 but expensive large-capacity tapes. One possible approach is to run amdump
315 with tapes only, say once a week, to perform full backups, and run it without
316 tape on the other days, so that it performs incremental backups and stores
317 them in the holding disk. Once or twice a week, you flush all backups in the
318 holding disk to a single tape.
319 If you don't trust your holding disk, and you'd rather have all your data on
320 tapes daily, you can create an alternate configuration, with two tapes, that
321 backs up the holding disk only, always as a full backup. You'd run this
322 configuration always after your regular backup, so you always have a complete
323 image of the holding disk on tape, just in case it fails.
324 How can I configure Amanda for long-term archiving?
325 The best approach is to create a separate configuration for your archive
326 backups. It should use a separate set of tapes, and have all dumptypes
327 configured with `record no', so it doesn't interfere with regular backups.
328 Can I backup separate disks of the same host in different configurations?
329 Yes, but you have to be careful. Amanda uses UDP to issue estimate and backup
330 requests and, although replies to backup requests are immediate (so that TCP
331 connections for the actual backup can be established), replies to estimate
332 requests are not and, while one request is being processed, any other request
333 is ignored. The effect is two-fold:
335 i. If another configuration requests for estimates, the request will be
336 ignored, and the requester will end up timing out;
337 ii. If another configuration has already finished the estimates, and is now
338 requesting for backups, the backup requests will time-out.
340 So, there are two easy ways out:
342 i. Ensure that the configurations never run concurrently, or
343 ii. set up two different installations of the Amanda server, using different
344 services names to contact the clients, i.e., different port numbers. This
345 can be attained with the configure flag --with-testing=<service-suffix>.
346 Yes, the flag name is not appropriate, but so what?
348 If you don't want to set up two installations of Amanda (I agree, it's
349 overkill), but you still want to back up disks of the same host in separate
350 configurations, you can set up Amanda so that one configuration only starts
351 after the first one has already finished its One possible way to work-around
352 this limitation is to start one configuration only after you know the
353 estimates for the first one have already finished (modifying the crontab
354 entries, according to history data). You'll also have to delay the starttime
355 (a dumptype option) of the disks in the first configuration, so that they
356 don't start backing up before the estimates of the second configuration
358 Can Amanda span large filesystems across multiple tapes?
360 This is an open project, looking for developers. If you'd like to help, please
361 take a look at the Amanda Ongoing Projects Page (http://www.amanda.org/
362 ongoing.php), where more up-to-date information is likely to be found about
364 Update September 2004: Refer to the archive of the amanda-hackers mailinglist
365 (http://marc.theaimsgroup.com/?l=amanda-hackers). A patch by John Stange is
366 being discussed there, which allows splitting and spanning.
367 The current work-around is to use GNU tar to back up subdirectories of the
368 huge filesystem separately. But be aware of the problems listed in the
369 question about "results missing".
370 What's the difference between option "skip-full" and "strategy nofull"?
371 "strategy nofull" is supposed to handle the following situation: you run a
372 full dump off-line once a millenium :-), because that disk isn't supposed to
373 change at all and, if it does, changes are minimal. Amanda will run only level
374 1 backups of that filesystem, to avoid the risk of overwriting a level 1
375 backup needed to do a restore. Remember, you run full dumps once a millenium,
376 and your tape cycle probably won't last that long :-)
377 "skip-full", OTOH, is supposed to let the user run full dumps off-line
378 regularly (i.e., as often as specified in the dumpcycle), while Amanda takes
379 care of the incrementals. Currently, Amanda will tell you when you're supposed
380 to run the level 0 backups but, if you fail to do so, Amanda will not only
381 skip a full day's worth of valuable backups of the filesystem, on the day it
382 told you to the full backup manually, but it will also run a level 1 backup on
383 the next day, even if you have not performed the full backup yet. Worse yet:
384 it might perform a level 2 on the next day, just after you have run the level
385 0, so, if the disk should crash, you'd have to restore a level 0 then a level
386 2, but not the level 1! Not a real problem, but definitely strange, eh?
387 Why does amdump report "results missing"?
388 One of the possible reasons is that you have requested too many backups of the
389 host. In this case, the estimate request or the reply may not fit in a UDP
390 packet. This will cause Amanda not to perform some of the backups. Fixing this
391 problem involves modifying the way estimate requests are issued, so that no
392 packet exceeds the maximum packet size, and issuing additional requests that
393 did not fit in a UDP packet after a reply for the previous set is obtained.
394 The probability of getting this problem has been considerably reduced since we
395 increased the maximum UDP packet size from 1Kb to 64Kb, but some operating
396 systems may not support such large packets.
397 One possible work-around is to try to shorten the pathnames of the directories
398 and the exclude file names, so that more requests fit in the UDP packet. You
399 may create short-named links in some directory closer to the root (/) so as to
400 reduce the length of names. I.e., instead of backing up /usr/home/foo and /
401 usr/home/bar, create the following links:
403 /.foo -> /usr/home/foo
404 /.bar -> /usr/home/bar
406 then list /.foo and /.bar in the disklist.
407 Another approach is to group sub-directories in backup sets, instead of
408 backing up them all separately. For example, create /usr/home/.bkp1 and move
409 `foo' and `bar' into it, then create links so that the original pathnames
410 remain functional. Then, list /usr/home/.bkp1 in the disklist. You may create
411 as many `.bkp<N>' directories as you need.
412 A simpler approach, that may work for you, is to backup only a subset of the
413 subdirectories of a filesystem separately. The others can be backed up
414 together with the root of the filesystem, using an exclude list that prevents
416 Why does amdump report "disk offline"?
417 Well, assuming the disk is not really off line :-), it may be a permission
418 problem, but then, amcheck would have reported it.
419 Another possible reason for this failure is a filesystem error, that causes
420 DUMP to crash before it estimates the backup size; a fsck may help.
421 Yet another possibility is that the filesystem is so large that the backup
422 program is incorrectly reporting the estimated size, for example, by printing
423 a negative value that Amanda will not accept as a valid estimate. If you are
424 using dump, contact your vendor and request a patch for dump that fixes this
425 bug. If you are using GNU-tar, make sure it is release 1.12 or newer; 1.11.8
426 won't do! Even release 1.12 may require a patch to correctly report estimates
427 and dump sizes, as well as to handle sparse files correctly and quickly
428 instead of printing error messages like `Read error at byte 0, reading 512
429 bytes, in file ./var/log/lastlog: Bad file number' in sendsize.debug and being
430 very slow. Check the patches directory of the Amanda distribution.
431 What if amdump reports "dumps way too big, must skip incremental dumps"?
432 It means Amanda couldn't back up some disk because it wouldn't fit in the tape
433 (s) you have configured Amanda to use. It considered performing some
434 incrementals instead of full dumps, so that all disks would fit, but this
435 wouldn't be enough, so the disk really had to be dropped in this run.
436 In general, you can just ignore this message if it happens only once in a
437 while. Low-priority disks are discarded first, so you'll hardly miss really
439 One real work-around is to configure Amanda to use more tapes: increase
440 `runtapes' in amanda.conf. Even if you don't have a real tape changer, you can
441 act yourself as a changer (`chg-manual'; more details in the question about
442 tape changer configuration), or use `chg-multi' with a single tape unit, and
443 lie to Amanda that it will have two tapes to use. If you have a holding disk
444 as large as a tape, and configure Amanda (2.4.1b1 or newer) not to reserve any
445 space for degraded dumps, dumps that would be stored in the second tape of a
446 run will be performed to the holding disk, so you can flush them to tape in
448 amdump reported "infofile update failed". What should I do?
449 Make sure all directories and files are readable and writable by the Amanda
450 user, within the directory you specified as `infofile' in amanda.conf. From
451 then on, only run amanda server commands ( amadmin, amdump, amflush,
452 amcleanup) as the Amanda user, not as root.
453 Why does Amanda sometimes promote full dumps?
454 To spread the full dumps along the dumpcycle, so that daily runs take roughly
455 the same amount of tape and time. As soon as you start using Amanda, it will
456 run full dumps of all filesystems. Then, on the following runs, it will
457 promote some backups, so as to adjust the balance. After one or two
458 dumpcycles, it should stop promoting dumps. You can see how well it is doing
459 with amadmin <conf> balance. If you find the results surprising, you may want
460 to adjust dumpcycle or runspercycle.
461 Why does amrecover report "no index records" or "disk not found"?
462 The most common cause of this problem is not having enabled index generation
463 in amanda.conf. The `index yes' option must be present in every dumptype for
464 whose disks indexes should be generated.
465 Another possibility is that amrecover is not selecting the configuration name
466 that contains the backups for the selected disk. You may specify a
467 configuration name with the `-C' switch, when you invoke amrecover. The
468 default configuration name can only be specified at Amanda configure time
469 (configure --with-config=<name>).
470 Indexes are currently generated at backup-time only, so, if a backup was
471 performed without creating an index, you won't be able to use amrecover to
472 restore it, you'll have to use amrestore.
473 Ok, I'm done with testing Amanda, now I want to put it in production. How can
474 I reset its databases so as to start from scratch?
475 First, remove the `curinfo' database. By default, it is a directory, but, if
476 you have selected any other database format (don't, they're deprecated), they
477 may be files with extensions such as .dir and .pag.
478 Then, remove any log files from the log directory: log.<TIMESTAMP>.<count> and
479 amdump.<count>. Finally, remove the tapelist file, stored in the directory
480 that contains amanda.conf, unless amanda.conf specifies otherwise. Depending
481 on the tape changer you have selected, you may also want to reset its state
483 The man-page of dump says that active filesystems may be backed up
484 inconsistently. What does Amanda do to prevent inconsistent backups?
485 Nothing. When you back up an active filesystem, there are two possibilities:
486 dump may print strange error messages about invalid blocks, then fail; in this
487 case, Amanda will retry the backup on the next run.
488 Files that are modified while dump runs may be backed up inconsistently. But
489 then, they will be included in the next incremental backup, which should
491 Large, critical files such as databases should be locked somehow, to avoid
492 inconsistent backups, but there's no direct support for that in Amanda. The
493 best bet is to configure Amanda to use a wrapper to dump, that locks and
494 unlocks the database when appropriate.
495 Which version of GNU-tar should I use?
496 (This answer was slightly adapted from a posting by Paul Bijnens
497 <paul.bijnens@xplanation.com>, Mon, 11 Apr 2005):
500 However it still sets return code 2 for some infrequent conditions even with
501 --ignore-failed-read option. This results in Amanda thinking the total
502 archive is bad, and drops the complete archive. Those conditions are very
503 rare on a quiet filesystem.
504 * 1.13.25 is good: no problems found (yet).
505 * 1.13.9x is not good.
506 It has changed the format of "tar -t", resulting in amrecover not able to
508 * 1.14.x is not good.
509 It writes good archives, but when restoring, it has trouble with sparse
510 files; the sparse file itself, and *all* files after it cannot be read
511 anymore. But you can read the archive with a good tar version (i.e. the tar
512 images produced are fine).
513 * 1.15.1 is good: no problems found (yet).
514 Paul Bijnens: "I'm using this version on most of my clients since january
515 this year (2005), and have already done successful restore too."
517 What does "bumping" mean?
518 The term "bumping" is used to describe the change from one backup-level to the
519 next higher level. If Amanda changes from Level 0 to Level 1 for a specific
521 The basic goal of "bumping" is to save precious space on the backup media as
522 higher level incremental backups are smaller in size than lower level
524 The disadvantage of increasing backup levels is the fact that restoring from
525 higher level incremental backups needs more tapes. This increases the amount
526 of work time that are needed to fully restore a DLE as well as the possibility
527 of tape-errors and similar problems during the process of restore. So in
528 general it is recommended to keep the levels as low as possible with the given
530 There are various amanda.conf parameters to control and fine-tune Amanda's
531 behavior when it comes to "bumping":
532 Please refer to the amanda-manpage and the example amanda.conf for details on
533 the parameters bumppercent, bumpsize, bumpdays and bumpmult.
534 How do I backup a Windows server?
535 Amanda is able to use smbclient to dump SMB/CIFS-shares. Refer to the Backup
536 PC_hosts_using_Samba for details.
537 How do I tell my iptables-based firewall to allow Amanda through?
538 posted by Matt Hyclak <hyclak@math.ohiou.edu>:
541 iptables -A INPUT -p udp -s $AMANDA_SERVER -d $AMANDA_CLIENT --dport
544 and load the ip_conntrack_amanda kernel module. I use the following in /etc/
547 options ip_conntrack_amanda master_timeout=2400
548 install ip_tables /sbin/modprobe --ignore-install ip_tables && /sbin/
549 modprobe ip_conntrack_amanda
551 This sets the UDP timeout for Amanda packets to 2400 seconds, up from the
552 default 300 (don't hold me to that, it might be 600). I was getting estimate
553 timeouts since they were taking longer than 300/600 seconds and the firewall
554 would close the port.
555 Makes things a little more secure than opening up everything > 1024 ;-)
556 How do I get rid of pressing "q" to get rid of a pager prompt when using
558 compiled from postings by Paul Bijnens <paul.bijnens@xplanation.com> and Jon
559 LaBadie <jon@jgcomp.com>
561 If you have to press "q" all the time in amrecover this is related to the
562 pager-binary you use. If you use Linux this will be most likely less. To teach
563 less to quit when hitting EOF, you need to set something like LESS=--QUIT-AT-
564 EOF; export LESS, for example in your .profile. Refer to the manpage of less
567 If you don't like the quit at EOF behavior "except" when in amrecover create
568 an alias or a wrapper; something like:
569 alias amrecov='LESS="$LESS -E" _pathto_your_amrecover'
570 Is there a way to tell the pager that my terminal has "y" lines?
571 Jon LaBadie <jon@jgcomp.com> wrote:
572 The pager normally does it's best to find out how many lines your terminal
573 has, given the right TERM-variable. Even terminals with elastic boundaries
574 (e.g. xterms) work. But I have to admit that on Solaris the settings are not
575 always correct. You can fix it quickly by setting an environment variable to
576 e.g. LINES=24 (and export it).
578 -------------------------------------------------------------------------------
581 Chapter 18. Using Amanda Home Chapter 20. Collection of the top ten Amanda
582 questions. And answers.