amanda.conf - Main configuration file for AMANDA, the Advanced Maryland Automatic Network Disk Archiver

amanda.conf is the main configuration file for AMANDA. This manpage lists the relevant sections and parameters of this file for quick reference.

There are a number of configuration parameters that control the behavior of the AMANDA programs. All have default values, so you need not specify the parameter in amanda.conf if the default is suitable.

Lines starting with # are ignored, as are blank lines. Comments may be placed on a line with a directive by starting the comment with a #. The remainder of the line is ignored.

Keywords are case insensitive, i.e. mailto and MailTo are treated the same.

Integer arguments may have one of the following (case insensitive) suffixes, some of which have a multiplier effect:

POSSIBLE SUFFIXES

PARAMETERS

The amanda.conf file may define one or more holding disks used as buffers to hold backup images before they are written to tape. The syntax is:

holdingdisk name { holdingdisk-option holdingdisk-value ... }.fi

Name is a logical name for this holding disk.

The options and values are:

comment string

Default: none. A comment string describing this holding disk.

directory disk

Default: /dumps/amanda. The path to this holding area.

use int

Default: 0 Gb. Amount of space that can be used in this holding disk area. If the value is zero, all available space on the file system is used. If the value is negative, AMANDA will use all available space minus that value.

chunksize int

Default: 1 Gb. Holding disk chunk size. Dumps larger than the specified size will be stored in multiple holding disk files. The size of each chunk will not exceed the specified value. However, even though dump images are split in the holding disk, they are concatenated as they are written to tape, so each dump image still corresponds to a single continuous tape section.

If 0 is specified, AMANDA will create holding disk chunks as large as ((INT_MAX/1024)-64) Kbytes.

Each holding disk chunk includes a 32 Kbyte header, so the minimum chunk size is 64 Kbytes (but that would be really silly).

Operating systems that are limited to a maximum file size of 2 Gbytes actually cannot handle files that large. They must be at least one byte less than 2 Gbytes. Since AMANDA works with 32 Kbyte blocks, and to handle the final read at the end of the chunk, the chunk size should be at least 64 Kbytes (2 * 32 Kbytes) smaller than the maximum file size, e.g. 2047 Mbytes.

The amanda.conf file may define multiple sets of backup options and refer to them by name from the disklist file. For instance, one set of options might be defined for file systems that can benefit from high compression, another set that does not compress well, another set for file systems that should always get a full backup and so on.

A set of backup options are entered in a dumptype section, which looks like this:

define dumptype name { dumptype-option dumptype-value ... }

Name is the name of this set of backup options. It is referenced from the disklist file.

Some of the options in a dumptype section are the same as those in the main part of amanda.conf. The main option value is used to set the default for all dumptype sections. For instance, setting dumpcycle to 50 in the main part of the config file causes all following dumptype sections to start with that value, but the value may be changed on a section by section basis. Changes to variables in the main part of the config file must be done before (earlier in the file) any dumptypes are defined.

The dumptype options and values are:

auth string

Default: bsd. Type of authorization to perform between tape server and backup client hosts. May be krb4 to use Kerberos-IV authorization.

bumpsize int

Default: 10 Mbytes. The minimum savings required to trigger an automatic bump from one incremental level to the next, expressed as size. If AMANDA determines that the next higher backup level will be this much smaller than the current level, it will do the next level. The value of this parameter is used only if the parameter bumppercent is set to 0.

See also the options bumppercent, bumpmult and bumpdays.

bumppercent int

Default: 0 percent. The minimum savings required to trigger an automatic bump from one incremental level to the next, expressed as percentage of the current size of the DLE (size of current level 0). If AMANDA determines that the next higher backup level will be this much smaller than the current level, it will do the next level.

If this parameter is set to 0, the value of the parameter bumpsize is used to trigger bumping.

See also the options bumpsize, bumpmult and bumpdays.

bumpmult float

Default: 1.5. The bump size multiplier. AMANDA multiplies bumpsize by this factor for each level. This prevents active filesystems from bumping too much by making it harder to bump to the next level. For example, with the default bumpsize and bumpmult set to 2.0, the bump threshold will be 10 Mbytes for level one, 20 Mbytes for level two, 40 Mbytes for level three, and so on.

bumpdays int

Default: 2 days. To insure redundancy in the dumps, AMANDA keeps filesystems at the same incremental level for at least bumpdays days, even if the other bump threshold criteria are met.

comment string

Default: none. A comment string describing this set of backup options.

comprate float [, float ]

Default: 0.50, 0.50. The expected full and incremental compression factor for dumps. It is only used if AMANDA does not have any history information on compression rates for a filesystem, so should not usually need to be set. However, it may be useful for the first time a very large filesystem that compresses very little is backed up.

compress [client|server] string

Default: client fast. If AMANDA does compression of the backup images, it can do so either on the backup client host before it crosses the network or on the tape server host as it goes from the network into the holding disk or to tape. Which place to do compression (if at all) depends on how well the dump image usually compresses, the speed and load on the client or server, network capacity, holding disk capacity, availability of tape hardware compression, etc.

For either type of compression, AMANDA also allows the selection of two styles of compression. Best is the best compression available, often at the expense of CPU overhead. Fast is often not as good a compression as best, but usually less CPU overhead.

So the compress options line may be one of:

•

compress none

•

compress [client] fast

•

compress [client] best

•

compress server fast

•

compress server best

Note that some tape devices do compression and this option has nothing to do with whether that is used. If hardware compression is used (usually via a particular tape device name or mt option), AMANDA (software) compression should be disabled.

dumpcycle int

Default: 10 days. The number of days in the backup cycle. Each disk using this set of options will get a full backup at least this often. Setting this to zero tries to do a full backup each run.

estimate client|calcsize|server

Default: client. Determine the way AMANDA does it's estimate.

•

client:

Use the same program as the dumping program, this is the most accurate way to do estimates, but it can take a long time.

•

calcsize:

Use a faster program to do estimates, but the result is less accurate.

•

server:

Use only statistics from the previous run to give an estimate, it takes only a few seconds but the result is not accurate if your disk usage changes from day to day.

exclude [ list|file ][[optional][ append ][ string ]+]

Default: file. There are two exclude lists, exclude file and exclude list. With exclude file , the string is a GNU-tar exclude expression. With exclude list , the string is a file name on the client containing GNU-tar exclude expressions.

All exclude expressions are concatenated in one file and passed to GNU-tar as an --exclude-from argument.

With the append keyword, the string is appended to the current list, without it, the string overwrites the list.

If optional is specified for exclude list, then amcheck will not complain if the file doesn't exist or is not readable.

For exclude list, if the file name is relative, the disk name being backed up is prepended. So if this is entered:

exclude list ".amanda.excludes" the actual file used would be /var/.amanda.excludes for a backup of /var, /usr/local/.amanda.excludes for a backup of /usr/local, and so on.

holdingdisk boolean

Default: yes. Whether a holding disk should be used for these backups or whether they should go directly to tape. If the holding disk is a portion of another file system that AMANDA is backing up, that file system should refer to a dumptype with holdingdisk set to no to avoid backing up the holding disk into itself.

ignore boolean

Default: no. Whether disks associated with this backup type should be backed up or not. This option is useful when the disklist file is shared among several configurations, some of which should not back up all the listed file systems.

include [ list|file ][[optional][ append ][ string ]+]

Default: file ".". There are two include lists, include file and include list. With include file , the string is a glob expression. With include list , the string is a file name on the client containing glob expressions.

All include expressions are expanded by AMANDA, concatenated in one file and passed to GNU-tar as a --files-from argument. They must start with "./" and contain no other "/".

With the append keyword, the string is appended to the current list, without it, the string overwrites the list.

If optional is specified for include list, then amcheck will not complain if the file doesn't exist or is not readable.

For include list, If the file name is relative, the disk name being backed up is prepended.

index boolean

Default: no. Whether an index (catalogue) of the backup should be generated and saved in indexdir. These catalogues are used by the amrecover utility.

kencrypt boolean

Default: no. Whether the backup image should be encrypted by Kerberos as it is sent across the network from the backup client host to the tape server host.

maxdumps int

Default: 1. The maximum number of backups from a single host that AMANDA will attempt to run in parallel. See also the main section parameter inparallel.

maxpromoteday int

Default: 10000. The maximum number of day for a promotion, set it 0 if you don't want promotion, set it to 1 or 2 if your disks get overpromoted.

priority string

Default: medium. When there is no tape to write to, AMANDA will do incremental backups in priority order to the holding disk. The priority may be high (2), medium (1), low (0) or a number of your choice.

program string

Default: DUMP. The type of backup to perform. Valid values are DUMP for the native operating system backup program, and GNUTAR to use GNU-tar or to do PC backups using Samba.

record boolean

Default: yes. Whether to ask the backup program to update its database (e.g. /etc/dumpdates for DUMP or /usr/local/var/amanda/gnutar-lists for GNUTAR) of time stamps. This is normally enabled for daily backups and turned off for periodic archival runs.

skip-full boolean

Default: no. If true and planner has scheduled a full backup, these disks will be skipped, and full backups should be run off-line on these days. It was reported that AMANDA only schedules level 1 incrementals in this configuration; this is probably a bug.

skip-incr boolean

Default: no. If true and planner has scheduled an incremental backup, these disks will be skipped.

starttime int

Default: none. Backups will not start until after this time of day. The value should be hh*100+mm, e.g. 6:30PM (18:30) would be entered as 1830.

strategy string

Default: standard. Strategy to use when planning what level of backup to run next. Values are:

standard

The standard AMANDA schedule.

nofull

Never do full backups, only level 1 incrementals.

noinc

Never do incremental backups, only full dumps.

skip

Never do backups (useful when sharing the disklist file).

incronly

Only do incremental dumps. amadmin force should be used to tell AMANDA that a full dump has been performed off-line, so that it resets to level 1. It is similar to skip-full, but with incronly full dumps may be scheduled manually. Unfortunately, it appears that AMANDA will perform full backups with this configuration, which is probably a bug.

The following dumptype entries are predefined by AMANDA:

define dumptype no-compress { compress none } define dumptype compress-fast { compress client fast } define dumptype compress-best { compress client best } define dumptype srvcompress { compress server fast } define dumptype bsd-auth { auth bsd } define dumptype krb4-auth { auth krb4 } define dumptype no-record { record no } define dumptype no-hold { holdingdisk no } define dumptype no-full { skip-full yes }

In addition to options in a dumptype section, one or more other dumptype names may be entered, which make this dumptype inherit options from other previously defined dumptypes. For instance, two sections might be the same except for the record option:

define dumptype normal { comment "Normal backup, no compression, do indexing" no-compress index yes maxdumps 2 } define dumptype testing { comment "Test backup, no compression, do indexing, no recording" normal record no }

AMANDA provides a dumptype named global in the sample amanda.conf file that all dumptypes should reference. This provides an easy place to make changes that will affect every dumptype.

The amanda.conf file may define multiple types of tape media and devices. The information is entered in a tapetype section, which looks like this in the config file:

define tapetype name { tapetype-option tapetype-value ... }

Name is the name of this type of tape medium/device. It is referenced from the tapetype option in the main part of the config file.

The tapetype options and values are:

comment string

Default: none. A comment string describing this set of tape information.

filemark int

Default: 1000 bytes. How large a file mark (tape mark) is, measured in bytes. If the size is only known in some linear measurement (e.g. inches), convert it to bytes using the device density.

length int

Default: 2000 kbytes. How much data will fit on a tape.

Note that this value is only used by AMANDA to schedule which backups will be run. Once the backups start, AMANDA will continue to write to a tape until it gets an error, regardless of what value is entered for length (but see the section OUTPUT DRIVERS in the amanda(8) manpage for exceptions).

blocksize int

Default: 32. How much data will be written in each tape record expressed in KiloBytes. The tape record size (= blocksize) can not be reduced below the default 32 KBytes. The parameter blocksize can only be raised if AMANDA was compiled with the configure option --with-maxtapeblocksize=N set with "N" greater than 32 during configure.

file-pad boolean

Default: true. If true, every record, including the last one in the file, will have the same length. This matches the way AMANDA wrote tapes prior to the availability of this parameter. It may also be useful on devices that only support a fixed blocksize.

Note that the last record on the tape probably includes trailing null byte padding, which will be passed back to gzip, compress or the restore program. Most programs just ignore this (although possibly with a warning).

If this parameter is false, the last record in a file may be shorter than the block size. The file will contain the same amount of data the dump program generated, without trailing null byte padding. When read, the same amount of data that was written will be returned.

speed int

Default: 200 bps. How fast the drive will accept data, in bytes per second. This parameter is NOT currently used by AMANDA.

lbl-templ string

A PostScript template file used by amreport to generate labels. Several sample files are provided with the AMANDA sources in the example directory. See the amreport(8) man page for more information.

In addition to options, another tapetype name may be entered, which makes this tapetype inherit options from another tapetype. For instance, the only difference between a DLT4000 tape drive using Compact-III tapes and one using Compact-IV tapes is the length of the tape. So they could be entered as:

define tapetype DLT4000-III { comment "DLT4000 tape drives with Compact-III tapes" length 12500 mbytes # 10 Gig tapes with some compression filemark 2000 kbytes speed 1536 kps } define tapetype DLT4000-IV { DLT4000-III comment "DLT4000 tape drives with Compact-IV tapes" length 25000 mbytes # 20 Gig tapes with some compression }

The amanda.conf file may define multiple types of network interfaces. The information is entered in an interface section, which looks like this:

define interface name { interface-option interface-value ... }

name is the name of this type of network interface. It is referenced from the disklist file.

Note that these sections define network interface characteristics, not the actual interface that will be used. Nor do they impose limits on the bandwidth that will actually be taken up by AMANDA. AMANDA computes the estimated bandwidth each file system backup will take based on the estimated size and time, then compares that plus any other running backups with the limit as another of the criteria when deciding whether to start the backup. Once a backup starts, AMANDA will use as much of the network as it can leaving throttling up to the operating system and network hardware.

The interface options and values are:

comment string

Default: none. A comment string describing this set of network information.

use int

Default: 300 Kbps. The speed of the interface in Kbytes per second.

In addition to options, another interface name may be entered, which makes this interface inherit options from another interface. At the moment, this is of little use.

James da Silva, <jds@amanda.org>: Original text

Stefan G. Weichinger, <sgw@amanda.org>, maintainer of the AMANDA-documentation: XML-conversion, major update, splitting

amanda(8),