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Chapter 19. Amanda FAQ
Prev Part IV. Various Information Next
-------------------------------------------------------------------------------
Chapter 19. Amanda FAQ
Amanda Core Team
AMANDA Core Team
Stefan G. Weichinger
XML-conversion;Updates
AMANDA Core Team
<sgw@amanda.org>
This file contains answers to some questions that are frequently asked in the
Amanda mailing lists, specially by new users. Please take a look at this file
before posting, this can save us time that could be spent improving Amanda and
its documentation.
New entries and modifications are welcome; send them to mailto://amanda-
users@amanda.org or mailto://amanda-hackers@amanda.org.
You may also want to take a look at the Amanda FAQ-O-Matic http://
www.amanda.org/fom-serve/cache/1.html.
Why_does_Amanda_fail_to_build_on_my_system?
Why_does_amdump_report_that_all_disks_failed?
Why_does_amcheck_say_"port_NNN_is_not_secure"?
Why_does_amcheck_claim_that_the_tape_is_"not_an_Amanda_tape"?
Why_does_amcheck_report_"selfcheck_request_timed_out"?
Why_does_amandad.debug_contain_"error_receiving_message"?
Why_does_amcheck_say_"access_as_<username>_not_allowed..."?
Why_does_amcheck_report_"ip_address_#.#.#.#"_is_not_in_the_ip_list_list_for
<hostname>'?
Why_does_amcheck_say_"cannot_overwrite_active_tape"?
Why_does_amcheck_tell_me_"DUMP_program_not_available"?
Which_tape_changer_configuration_should_I_use_in_amanda.conf?
Where_do_I_get_my_tapetype-definition_from?_Do_I_have_to_run_amtapetype?
Should_I_use_software_or_hardware_compression?
How_can_I_configure_Amanda_so_that_it_performs_full_backups_on_the_week-end
and_incrementals_on_weekdays?
What_if_my_tape_unit_uses_expensive_tapes,_and_I_don't_want_to_use_one_tape
per_day?_Can't_Amanda_append_to_tapes?
How_can_I_configure_Amanda_for_long-term_archiving?
Can_I_backup_separate_disks_of_the_same_host_in_different_configurations?
Can_Amanda_span_large_filesystems_across_multiple_tapes?
What's_the_difference_between_option_"skip-full"_and_"strategy_nofull"?
Why_does_amdump_report_"results_missing"?
Why_does_amdump_report_"disk_offline"?
What_if_amdump_reports_"dumps_way_too_big,_must_skip_incremental_dumps"?
amdump_reported_"infofile_update_failed"._What_should_I_do?
Why_does_Amanda_sometimes_promote_full_dumps?
Why_does_amrecover_report_"no_index_records"_or_"disk_not_found"?
Ok,_I'm_done_with_testing_Amanda,_now_I_want_to_put_it_in_production._How_can
I_reset_its_databases_so_as_to_start_from_scratch?
The_man-page_of_dump_says_that_active_filesystems_may_be_backed_up
inconsistently._What_does_Amanda_do_to_prevent_inconsistent_backups?
Which_version_of_GNU-tar_should_I_use?
What_does_"bumping"_mean?
How_do_I_backup_a_Windows_server?
How_do_I_tell_my_iptables-based_firewall_to_allow_Amanda_through?
How_do_I_get_rid_of_pressing_"q"_to_get_rid_of_a_pager_prompt_when_using
amrecover?
Is_there_a_way_to_tell_the_pager_that_my_terminal_has_"y"_lines?
Why does Amanda fail to build on my system?
One of the most common reasons for compile-time errors is stale information in
config.cache, after a build on a different platform using the same build tree.
In order to avoid this problem, make sure you don't ever reuse build trees
across platforms, or at least run make distclean before running configure on
another platform.
Another common reason for failure, that causes link-time errors, is a problem
in libtool that causes it to search for symbols in already-installed amanda
libraries, instead of in the just-built ones. This problem is known to affect
SunOS 4.1.3 and FreeBSD. You can usually work around it by specifying a
different prefix when you configure the new version of Amanda. However, it may
not work if the previous version of Amanda was installed in /usr/local and gcc
searches this directory by default; in this case, you must either remove the
old libraries (which you don't want to do, right? :-) or call configure with
the flag --disable-libtool. In this case, Amanda won't create shared
libraries, so binaries will be larger, but you may worry about that later.
You may also want to take a look at Amanda_2.5.0_-_System-Specific
Installation_Notes, as well as to the Amanda Patches Page (http://
www.amanda.org/patches/) for other known problems. If everything fails, you
should read the manual, but since we don't have one yet, just post a help
request to the amanda-users mailing list (mailto://amanda-users@amanda.org),
showing the last few lines of the failed build.
Why does amdump report that all disks failed?
Probably because the Amanda clients are not properly configured. Before you
ever run amdump, make sure amcheck succeeds. When it does, so should amdump.
Make sure you run amcheck as the same user that is supposed to start amdump,
otherwise you may get incorrect results.
Why does amcheck say "port NNN is not secure"?
Because amcheck, as some other Amanda programs, must be installed as setuid-
root. Run make install as "root", or chown all Amanda setuid programs to
"root", then chown u+s them again, if chown drops the setuid bit.
Why does amcheck claim that the tape is "not an Amanda tape"?
Because Amanda requires you to label tapes before it uses them. Run amlabel in
order to label a tape.
If, even after labeling a tape, amcheck still complains about it, make sure
the regular expression specified in amanda.conf matches the label you have
specified, and check whether you have configured non-rewinding tape devices
for Amanda to use. For example, use /dev/nrst0 instead of /dev/rst0, /dev/rmt/
0bn instead of /dev/rmt/0b, or some other system-dependent device name that
contains an "n", instead of one that does not. The "n" stands for non-
rewinding.
If you have labeled any tapes using the rewiding device configuration, you'll
have to label them again.
Why does amcheck report "selfcheck request timed out"?
This can occur under several different situations. First, make sure this
problem is repeatable; if Amanda programs are NFS-auto-mounted, some clients
may fail to mount the Amanda binaries in time.
If the error is repeatable, log into the client, and check whether the
directory /tmp/amanda exists, and a file named amandad.debug exists in there:
amandad will create this file whenever it starts. If this file does not exist,
amandad is not starting properly, or it lacks permission to create /tmp/
amanda/amandad.debug.
In the latter case, wipe out /tmp/amanda, and amandad should create it next
time it runs. In the former case, check your inetd configuration. Make sure
you have added the Amanda services to /etc/services (or the NIS services map),
that /etc/inetd.conf was properly configured, and that you have signalled
inetd to reread this file (some systems may need rebooting). Check section 2.2
from in the Amanda_Installation_Notes for details. Check the inetd man-page
for possible differences between the standard format of /etc/inetd.conf and
the one in your system.
Pay special attention to typos in /etc/inetd.conf; error messages will
probably appear in /var/adm/messages or /var/log/messages if you have typed
the amandad program name incorrectly. Make sure the same user that you have
specified at configure-time (configure --with-user=<USERNAME>) is listed in /
etc/inetd.conf. Check whether this user has permission to run amandad, as well
as any shared libraries amandad depends upon, by running the specified amandad
command by hand, as the Amanda user. It should just time-out after 30 seconds
waiting for a UDP packet. If you type anything, it will abort immediately,
because it can't read a UDP packet from the keyboard.
As soon as you have properly configured /etc/inetd.conf so as to run amandad,
you should no longer get the "selfcheck request timed out" message. A nice
tool to help make sure inetd is really listening on the amandad port is lsof,
available at ftp://vic.cc.purdue.edu/pub/tools/unix/lsof.
Why does amandad.debug contain "error receiving message"?
One possibility is that you have run amandad from the command line prompt and
typed anything instead of waiting for it to time-out: in this case, it will
try to read a UDP packet from the keyboard, and this was reported not to work
on most keyboards :-). However, if you have run amandad as any user other than
the one listed in /etc/inetd.conf, it may have created a /tmp/amanda directory
that the Amanda user cannot write to, so you should wipe it out.
Another possibility is that the Amanda service was not properly configured as
a UDP service; check /etc/services and /etc/inetd.conf.
Why does amcheck say "access as <username> not allowed..."?
There must be something wrong with .amandahosts configuration (or .rhosts, if
you have configured --without-amandahosts).
First, if the <username> is not what you expect (i.e., not what you have
specified in the --with-user flag, at configure time), check the inetd
configuration file: you must have specified the wrong username there.
Make sure you specify the names exactly as they appear in the error message
after the `@' sign in .amandahosts/.rhosts. You'll need a fully-qualified
domain name or not, depending on how your client resolves IP addresses to host
names.
Why does amcheck report "ip address #.#.#.#" is not in the ip list list for
<hostname>'?
Check your DNS configuration tables. In order to avoid DNS-spoofing, Amanda
double-checks hostname<->IP address mapping. If the IP address the request
comes from maps to a hostname, but this hostname does not map back to the
incoming IP address, the request is denied.
Why does amcheck say "cannot overwrite active tape"?
Because, if you configure Amanda to use N tapes, by setting tapecycle to N in
amanda.conf, before Amanda overwrites a tape, it must write to at least other
N-1 tapes. Of course, Amanda will always refuse to overwrite a tape marked for
`noreuse' with amadmin. Furthermore, such tapes are not counted when Amanda
computes `N-1' tapes.
If, for some reason, you want to tell Amanda to overwrite a particular tape,
regardless of its position in the cycle, use amrmtape. This command will
remove this tape from the tapelist file, that is used to manage the tape
cycle, and will delete information about backups stored in that tape from the
Amanda database.
Why does amcheck tell me "DUMP program not available"?
Because configure could not find dump when it was first run. This is a common
problem on Linux hosts, because most Linux distributions do not install dump
by default.
If you don't have a DUMP program installed, install it, remove config.cache,
run configure again and rebuild Amanda. While configure is running, make sure
it can find the installed DUMP program. If it cannot, you may have to set the
environment variables DUMP and RESTORE by hand, before running configure.
If you can't or don't want to install DUMP, you may use GNU tar, but make sure
it as release 1.12 or newer; release 1.11.8 may work, but estimates will be
slow as hell.
Which tape changer configuration should I use in amanda.conf?
If you only have one tape unit, you have two choices:
i. Don't use a tape changer at all, i.e., set runtapes to 1, set tapedev to
the non-rewinding device corresponding to the tape unit, and comment out
tpchanger, changerfile and changerdev
ii. Set up chg-manual, so that you can change tapes manually. If you select
chg-manual, you will not be able to start amdump as a cron job, and you
should always run amflush -f, because chg-manual will ask you to press
return in the terminal where you started the controlling program.
If you have several tape units, which you want to use to emulate a tape
changer, you want chg-multi. Even if you do own a real tape changer, that
operates based on ejecting a tape or such, chg-multi may be useful.
Actual tape changers usually require specialized changer programs, such as
mtx, chio or specific system calls. The availability of these programs is much
more dependent on the operating system you're running than on the particular
tape changer hardware you have.
mtx, for example, is available for several platforms. However, even if you
find it for your platform, beware that there exist several different programs
named mtx, that require different command line arguments, and print different
output, and Amanda's chg-mtx does not support them all. You may have to edit
the script, which shouldn't be hard to do.
In section BUILT-IN TAPE CHANGERS of Amanda_Tape_Changer_Support you will find
details about the tape changer interfacing programs provided with Amanda, that
can interact with common tape changer programs and with tape changer-related
system calls provided by some operating system. If none of them matches your
needs, you may have to develop your own tape changer interface script.
Before posting a question to the Amanda mailing lists, *please* search the
archives, and try to obtain as much information about driving your tape
changer hardware from the vendor of the changer hardware and of the operating
system, rather than from the Amanda mailing lists. We usually don't have much
to say about tape changer units, and several questions about them remain
unanswered. :-(
Anyway, if you decide to post a question, make sure you specify both the tape
changer hardware *and* the OS/platform that is going to interface with it.
Good luck! :-)
Where do I get my tapetype-definition from? Do I have to run amtapetype?
It is not mandatory to run amtapetype at installation-time. It is very likely
that your tapedrive or -changer is one of the devices that are already covered
by one of the existing tapetype-definitions.
You may find tapetype-definitions in the example amanda.conf, in the
mailinglist-archives of the amanda-users-mailinglist at http://
marc.theaimsgroup.com/?l=amanda-users or in the Amanda-FAQ-O-Matic at http://
www.amanda.org/fom-serve/cache/1.html.
Reasons to run amtapetype for your device:
* You want to generate your own tapetype-definition because you can't find any
suitable tapetype-definition for your device.
* You want to determine the performance of your device.
* You want to determine if your device has hardware-compression enabled.
If you decide to run amtapetype, please refer to the chapter Tapetypes and the
manpage amtapetype(8).
Should I use software or hardware compression?
When you enable software compression, you drastically reduce the compression
that might be achieved by hardware. In fact, tape drives will usually use
*more* tape if you tell them to try to further compress already compressed
data.
Thus, you must choose whether you're going to use software or hardware
compression; don't ever enable both unless you want to waste tape space.
Since Amanda prefers to have complete information about tape sizes and
compression rates, it can do a better job if you use software compression.
However, if you can't afford the extra CPU usage, Amanda can live with the
unpredictability of hardware compression, but you'll have to be very
conservative about the specified tape size, specially if there are filesystems
that contain mostly uncompressible data.
You might want to run amtapetype to determine if you have hardware-compression
enabled for your tape-drive.
How can I configure Amanda so that it performs full backups on the week-end
and incrementals on weekdays?
You can't. Amanda doesn't work this way. You just have to tell Amanda how many
tapes you have (tapecycle), and how often you want it to perform full backups
of each filesystem (dumpcycle). If you don't run it once a daily (including
Saturdays and Sundays :-), you'll also want to tell Amanda how many times
you'll run it per dumpcycle (runspercycle). It will spread full backups along
the dumpcycle, so you won't have any full-only or incremental-only runs.
Please also refer to "the friday-tape-question" in Collection_of_the_top_ten
Amanda_questions._And_answers..
What if my tape unit uses expensive tapes, and I don't want to use one tape
per day? Can't Amanda append to tapes?
It can't, and this is good. Tape drives and OS drivers are (in)famous for
rewinding tapes at unexpected times, without telling the program that's
writing to them. If you have a month's worth of backups in that tape, you
really don't want them to be overwritten, so Amanda has taken the safe
approach of requiring tapes to be written from the beginning on every run.
This can be wasteful, specially if you have a small amount of data to back up,
but expensive large-capacity tapes. One possible approach is to run amdump
with tapes only, say once a week, to perform full backups, and run it without
tape on the other days, so that it performs incremental backups and stores
them in the holding disk. Once or twice a week, you flush all backups in the
holding disk to a single tape.
If you don't trust your holding disk, and you'd rather have all your data on
tapes daily, you can create an alternate configuration, with two tapes, that
backs up the holding disk only, always as a full backup. You'd run this
configuration always after your regular backup, so you always have a complete
image of the holding disk on tape, just in case it fails.
How can I configure Amanda for long-term archiving?
The best approach is to create a separate configuration for your archive
backups. It should use a separate set of tapes, and have all dumptypes
configured with `record no', so it doesn't interfere with regular backups.
Can I backup separate disks of the same host in different configurations?
Yes, but you have to be careful. Amanda uses UDP to issue estimate and backup
requests and, although replies to backup requests are immediate (so that TCP
connections for the actual backup can be established), replies to estimate
requests are not and, while one request is being processed, any other request
is ignored. The effect is two-fold:
i. If another configuration requests for estimates, the request will be
ignored, and the requester will end up timing out;
ii. If another configuration has already finished the estimates, and is now
requesting for backups, the backup requests will time-out.
So, there are two easy ways out:
i. Ensure that the configurations never run concurrently, or
ii. set up two different installations of the Amanda server, using different
services names to contact the clients, i.e., different port numbers. This
can be attained with the configure flag --with-testing=<service-suffix>.
Yes, the flag name is not appropriate, but so what?
If you don't want to set up two installations of Amanda (I agree, it's
overkill), but you still want to back up disks of the same host in separate
configurations, you can set up Amanda so that one configuration only starts
after the first one has already finished its One possible way to work-around
this limitation is to start one configuration only after you know the
estimates for the first one have already finished (modifying the crontab
entries, according to history data). You'll also have to delay the starttime
(a dumptype option) of the disks in the first configuration, so that they
don't start backing up before the estimates of the second configuration
finish.
Can Amanda span large filesystems across multiple tapes?
Not yet :-(
This is an open project, looking for developers. If you'd like to help, please
take a look at the Amanda Ongoing Projects Page (http://www.amanda.org/
ongoing.php), where more up-to-date information is likely to be found about
this project.
Update September 2004: Refer to the archive of the amanda-hackers mailinglist
(http://marc.theaimsgroup.com/?l=amanda-hackers). A patch by John Stange is
being discussed there, which allows splitting and spanning.
The current work-around is to use GNU tar to back up subdirectories of the
huge filesystem separately. But be aware of the problems listed in the
question about "results missing".
What's the difference between option "skip-full" and "strategy nofull"?
"strategy nofull" is supposed to handle the following situation: you run a
full dump off-line once a millenium :-), because that disk isn't supposed to
change at all and, if it does, changes are minimal. Amanda will run only level
1 backups of that filesystem, to avoid the risk of overwriting a level 1
backup needed to do a restore. Remember, you run full dumps once a millenium,
and your tape cycle probably won't last that long :-)
"skip-full", OTOH, is supposed to let the user run full dumps off-line
regularly (i.e., as often as specified in the dumpcycle), while Amanda takes
care of the incrementals. Currently, Amanda will tell you when you're supposed
to run the level 0 backups but, if you fail to do so, Amanda will not only
skip a full day's worth of valuable backups of the filesystem, on the day it
told you to the full backup manually, but it will also run a level 1 backup on
the next day, even if you have not performed the full backup yet. Worse yet:
it might perform a level 2 on the next day, just after you have run the level
0, so, if the disk should crash, you'd have to restore a level 0 then a level
2, but not the level 1! Not a real problem, but definitely strange, eh?
Why does amdump report "results missing"?
One of the possible reasons is that you have requested too many backups of the
host. In this case, the estimate request or the reply may not fit in a UDP
packet. This will cause Amanda not to perform some of the backups. Fixing this
problem involves modifying the way estimate requests are issued, so that no
packet exceeds the maximum packet size, and issuing additional requests that
did not fit in a UDP packet after a reply for the previous set is obtained.
The probability of getting this problem has been considerably reduced since we
increased the maximum UDP packet size from 1Kb to 64Kb, but some operating
systems may not support such large packets.
One possible work-around is to try to shorten the pathnames of the directories
and the exclude file names, so that more requests fit in the UDP packet. You
may create short-named links in some directory closer to the root (/) so as to
reduce the length of names. I.e., instead of backing up /usr/home/foo and /
usr/home/bar, create the following links:
/.foo -> /usr/home/foo
/.bar -> /usr/home/bar
then list /.foo and /.bar in the disklist.
Another approach is to group sub-directories in backup sets, instead of
backing up them all separately. For example, create /usr/home/.bkp1 and move
`foo' and `bar' into it, then create links so that the original pathnames
remain functional. Then, list /usr/home/.bkp1 in the disklist. You may create
as many `.bkp<N>' directories as you need.
A simpler approach, that may work for you, is to backup only a subset of the
subdirectories of a filesystem separately. The others can be backed up
together with the root of the filesystem, using an exclude list that prevents
duplicate backups.
Why does amdump report "disk offline"?
Well, assuming the disk is not really off line :-), it may be a permission
problem, but then, amcheck would have reported it.
Another possible reason for this failure is a filesystem error, that causes
DUMP to crash before it estimates the backup size; a fsck may help.
Yet another possibility is that the filesystem is so large that the backup
program is incorrectly reporting the estimated size, for example, by printing
a negative value that Amanda will not accept as a valid estimate. If you are
using dump, contact your vendor and request a patch for dump that fixes this
bug. If you are using GNU-tar, make sure it is release 1.12 or newer; 1.11.8
won't do! Even release 1.12 may require a patch to correctly report estimates
and dump sizes, as well as to handle sparse files correctly and quickly
instead of printing error messages like `Read error at byte 0, reading 512
bytes, in file ./var/log/lastlog: Bad file number' in sendsize.debug and being
very slow. Check the patches directory of the Amanda distribution.
What if amdump reports "dumps way too big, must skip incremental dumps"?
It means Amanda couldn't back up some disk because it wouldn't fit in the tape
(s) you have configured Amanda to use. It considered performing some
incrementals instead of full dumps, so that all disks would fit, but this
wouldn't be enough, so the disk really had to be dropped in this run.
In general, you can just ignore this message if it happens only once in a
while. Low-priority disks are discarded first, so you'll hardly miss really
important data.
One real work-around is to configure Amanda to use more tapes: increase
`runtapes' in amanda.conf. Even if you don't have a real tape changer, you can
act yourself as a changer (`chg-manual'; more details in the question about
tape changer configuration), or use `chg-multi' with a single tape unit, and
lie to Amanda that it will have two tapes to use. If you have a holding disk
as large as a tape, and configure Amanda (2.4.1b1 or newer) not to reserve any
space for degraded dumps, dumps that would be stored in the second tape of a
run will be performed to the holding disk, so you can flush them to tape in
the morning.
amdump reported "infofile update failed". What should I do?
Make sure all directories and files are readable and writable by the Amanda
user, within the directory you specified as `infofile' in amanda.conf. From
then on, only run amanda server commands ( amadmin, amdump, amflush,
amcleanup) as the Amanda user, not as root.
Why does Amanda sometimes promote full dumps?
To spread the full dumps along the dumpcycle, so that daily runs take roughly
the same amount of tape and time. As soon as you start using Amanda, it will
run full dumps of all filesystems. Then, on the following runs, it will
promote some backups, so as to adjust the balance. After one or two
dumpcycles, it should stop promoting dumps. You can see how well it is doing
with amadmin <conf> balance. If you find the results surprising, you may want
to adjust dumpcycle or runspercycle.
Why does amrecover report "no index records" or "disk not found"?
The most common cause of this problem is not having enabled index generation
in amanda.conf. The `index yes' option must be present in every dumptype for
whose disks indexes should be generated.
Another possibility is that amrecover is not selecting the configuration name
that contains the backups for the selected disk. You may specify a
configuration name with the `-C' switch, when you invoke amrecover. The
default configuration name can only be specified at Amanda configure time
(configure --with-config=<name>).
Indexes are currently generated at backup-time only, so, if a backup was
performed without creating an index, you won't be able to use amrecover to
restore it, you'll have to use amrestore.
Ok, I'm done with testing Amanda, now I want to put it in production. How can
I reset its databases so as to start from scratch?
First, remove the `curinfo' database. By default, it is a directory, but, if
you have selected any other database format (don't, they're deprecated), they
may be files with extensions such as .dir and .pag.
Then, remove any log files from the log directory: log.<TIMESTAMP>.<count> and
amdump.<count>. Finally, remove the tapelist file, stored in the directory
that contains amanda.conf, unless amanda.conf specifies otherwise. Depending
on the tape changer you have selected, you may also want to reset its state
file.
The man-page of dump says that active filesystems may be backed up
inconsistently. What does Amanda do to prevent inconsistent backups?
Nothing. When you back up an active filesystem, there are two possibilities:
dump may print strange error messages about invalid blocks, then fail; in this
case, Amanda will retry the backup on the next run.
Files that are modified while dump runs may be backed up inconsistently. But
then, they will be included in the next incremental backup, which should
usually be enough.
Large, critical files such as databases should be locked somehow, to avoid
inconsistent backups, but there's no direct support for that in Amanda. The
best bet is to configure Amanda to use a wrapper to dump, that locks and
unlocks the database when appropriate.
Which version of GNU-tar should I use?
(This answer was slightly adapted from a posting by Paul Bijnens
<paul.bijnens@xplanation.com>, Mon, 11 Apr 2005):
* 1.13.19 is good.
However it still sets return code 2 for some infrequent conditions even with
--ignore-failed-read option. This results in Amanda thinking the total
archive is bad, and drops the complete archive. Those conditions are very
rare on a quiet filesystem.
* 1.13.25 is good: no problems found (yet).
* 1.13.9x is not good.
It has changed the format of "tar -t", resulting in amrecover not able to
use the indexes.
* 1.14.x is not good.
It writes good archives, but when restoring, it has trouble with sparse
files; the sparse file itself, and *all* files after it cannot be read
anymore. But you can read the archive with a good tar version (i.e. the tar
images produced are fine).
* 1.15.1 is good: no problems found (yet).
Paul Bijnens: "I'm using this version on most of my clients since january
this year (2005), and have already done successful restore too."
What does "bumping" mean?
The term "bumping" is used to describe the change from one backup-level to the
next higher level. If Amanda changes from Level 0 to Level 1 for a specific
DLE, it "bumps".
The basic goal of "bumping" is to save precious space on the backup media as
higher level incremental backups are smaller in size than lower level
incremental backups.
The disadvantage of increasing backup levels is the fact that restoring from
higher level incremental backups needs more tapes. This increases the amount
of work time that are needed to fully restore a DLE as well as the possibility
of tape-errors and similar problems during the process of restore. So in
general it is recommended to keep the levels as low as possible with the given
hardware and data.
There are various amanda.conf parameters to control and fine-tune Amanda's
behavior when it comes to "bumping":
Please refer to the amanda-manpage and the example amanda.conf for details on
the parameters bumppercent, bumpsize, bumpdays and bumpmult.
How do I backup a Windows server?
Amanda is able to use smbclient to dump SMB/CIFS-shares. Refer to the Backup
PC_hosts_using_Samba for details.
How do I tell my iptables-based firewall to allow Amanda through?
posted by Matt Hyclak <hyclak@math.ohiou.edu>:
Use something like
iptables -A INPUT -p udp -s $AMANDA_SERVER -d $AMANDA_CLIENT --dport
10080 -j ACCEPT
and load the ip_conntrack_amanda kernel module. I use the following in /etc/
modprobe.conf:
options ip_conntrack_amanda master_timeout=2400
install ip_tables /sbin/modprobe --ignore-install ip_tables && /sbin/
modprobe ip_conntrack_amanda
This sets the UDP timeout for Amanda packets to 2400 seconds, up from the
default 300 (don't hold me to that, it might be 600). I was getting estimate
timeouts since they were taking longer than 300/600 seconds and the firewall
would close the port.
Makes things a little more secure than opening up everything > 1024 ;-)
How do I get rid of pressing "q" to get rid of a pager prompt when using
amrecover?
compiled from postings by Paul Bijnens <paul.bijnens@xplanation.com> and Jon
LaBadie <jon@jgcomp.com>
Paul Bijnens wrote:
If you have to press "q" all the time in amrecover this is related to the
pager-binary you use. If you use Linux this will be most likely less. To teach
less to quit when hitting EOF, you need to set something like LESS=--QUIT-AT-
EOF; export LESS, for example in your .profile. Refer to the manpage of less
for details.
Jon LaBadie wrote:
If you don't like the quit at EOF behavior "except" when in amrecover create
an alias or a wrapper; something like:
alias amrecov='LESS="$LESS -E" _pathto_your_amrecover'
Is there a way to tell the pager that my terminal has "y" lines?
Jon LaBadie <jon@jgcomp.com> wrote:
The pager normally does it's best to find out how many lines your terminal
has, given the right TERM-variable. Even terminals with elastic boundaries
(e.g. xterms) work. But I have to admit that on Solaris the settings are not
always correct. You can fix it quickly by setting an environment variable to
e.g. LINES=24 (and export it).
Note
Refer to http://www.amanda.org/docs/faq.html for the current version of this
document.
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