Backup server (old)

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Deprecated
See Getting Started with Amanda instead

Contents

Server configuration file - amanda.conf

Please see amanda.conf(5) for information on amanda.conf parameters.

Client configuration file - disklist

The disklist file on the Amanda server describes the list of disk list entries (DLEs, usually directories or filesystem devices) to be backed up by the Amanda configuration. A number of parameters can be specified for each DLE either directly in the disklist or in a dumptype definition in amanda.conf. For more information on the disklist, see amanda(8).

Exclude and include lists

POSIX filenames in configuration files

Amanda 2.5.1 supports the POSIX path naming standard for all filenames in dumptype configuration in amanda.conf(5) and disklist configuration file.

This feature makes configuration of Amanda clients running Windows and Amanda clients that use international character sets possible.

Any filename referenced, including include file names, may contain any character except a NULL ('\0') character. Actual path interpretation is system dependent. POSIX file name rules are also allowed when specifying configuration file tags.

For example we use spaces in a dumptype name in the examples below.

Specifying Special characters

Pathnames with special characters must be enclosed in double quotes ("). Some unprintable charactes are given special escape sequences.

Escape sequences
Sequence Character
\n Newline
\r Carrage Return
\t Tab
\f Formfeed
\" Double Quote


Example: Spaces in a dumptype name, exclude list, include list in amanda.conf

 define dumptype "user-tar (a1)" {
    root-tar
    comment "User partition dumped with tar and a funny dumptype name"
    priority medium
    exclude "diskfile b*"
    include list "/tmp/include list with spaces in file name"
 }

Example: Disklist file entries with spaces in backup directory and dumptype names

 localhost "/tmp/disk name with spaces" user-tar
 localhost "/tmp/disk name with\nnewline" "user-tar (a1)"

Example: Using file names with spaces in Amrecover sub-commands

 setdisk "/tmp/disk name with\nnewline"
 add "diskfile *"
 delete "diskfile a1"

Device configuration

Tapetypes

Tapetype definitions are specified in amanda.conf configuration file. The tapetype definition provides AMANDA how much it is supposed to be able to store in a tape (length), how much space is wasted at the end of a dump image with the EOF mark (filemark) and how fast the tape unit is (speed).

The most important parameter is length, since AMANDA may decide to delay a backup if length is too small, but, if it is too large, AMANDA may end up leaving dumps in the holding disk or having to abort some dump.

Filemark is important if you have many disks, particularly with small incremental backups. The space wasted by so many filemarks may add up and considerably modify the available tape space.

The speed is currently unused.

AMANDA provides the amtapetype(8) utility to calculate the size of a tape, to generate a "tapetype" entry for your amanda.conf.

Specifying the appropriate tape device, but beware that it may take many hours to run (it fills the tape twice ...). Make sure you do not use hardware compression, even if you plan to use hardware compression in the future. amtapetype writes random data to tape, and random data will expand instead of compressing, therefore you'll get an estimate that's smaller than expected.

Some tapetype definitions are available here.

Changers

This part has been moved to a separate page.

See Changers.

RAIT

RAIT is an acronym for "Redundant Array of Inexpensive Tapes", where data is striped over several tape drives, with one drive writing an exclusive-or-sum of the others which can be used for error recovery. Any one of the data streams can be lost, and the data can still be recovered.

This means that a 3-drive RAIT set will write 2 "data" streams and one "parity" stream, and give you twice the capacity, twice the throughput, and the square of the failure rate (i.e. a 1/100 failure rate becomes 1/10,000, since a double-tape failure is required to lose data).

This means you can back up partitions as large as twice or four times your tape size with Amanda, with higher reliability and speed.

RAIT can also be used to mirror a backup to two drives, even when one of them is a virtual tape and the other is a real tape.

See Rait for a more complete description.

File driver/Disk backups

This driver uses files on disk as virtual tapes. Amanda can write to and read from virtual tapes, just like real tapes. A bunch of virtual tapes can even be manipulated with a changer.

Possible Uses

  • Test installations: You can easily explore the rich features of Amanda on systems without tape drives.
  • Inexpensive installations: Without buying a tape drive you can enjoy the benefits of Amanda and backup to a bunch of internal or external harddisks connected with Firewire or USB. You can create CD/DVD-sized backups which you can burn onto optical disks later.
  • Disk-based installations: You can use the file driver to backup onto a set of virtual tapes hosted on a bunch of hard-disks or a RAID-system. Combined with another Amanda configuration that dumps the virtual tapes to real tapes, you can provide reliable backup with faster tapeless recovery. This is called "disk-to-disk-to-tape" backup by some people today.

See File driver for a more complete description of virtual tapes, and their use.

Server-side and Client-side encryption

This section has been moved to a separate page.

See Encryption.

Custom Compression

  • compress client custom
    • Specify client_custom_compress "PROG"
    • PROG must not contain white space and it must accept -d for uncompress.
  • compress server custom
    • Specify server_custom_compress "PROG"
    • PROG must not contain white space and it must accept -d for uncompress.
  • sample dumptype:
 define dumptype custom-tar {
 global
 program "GNUTAR"
 comment "root partitions dumped with custom compression"
 compress server custom
 server_custom_compress "/usr/bin/my_gzip"
 priority low
}
  • I have tested custom compression using bzip2. Dumps works fine. Amrestore has a glitch on which

the image gets uncompressed correctly and written to a temp file but gets a broken-pipe error. I am investigating the problem.


Tape hardware compression

This section has been moved to a separate page.

See: Hardware compression.

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