The automatic backup data of each host sent to the host operating as a centralized Amanda server. To restore data, the host sends a request to the Amanda server, specifying the file system, data, and filenames. A server is installed with an amanda-server package and client with the amanda-client package. The clients may have different configurations and operating systems.
The Amanda server runs through xinetd using xinetd service located in /etc/xinetd.d. The three services files include: amanda, amidxtape, amandaidx. For a client to recover a backup from the server, a hostname is placed in the .amandahosts file in the server Amanda user's directory /var/lib/amanda. The file /var/lib/amanda/.amandahosts lists all the hosts that are backed by Amanda.
- amdump: performs automatic requested non-interactive backups for the file systems listed in the disklist configuration file, placed within cron instruction to run at a specified time.
- amflush: if, for any reason, amdump cannot save all its data to a backup medium, then it will retain the data on the holding disk, which later written with the amflush command. It directly backup data from the holding disk to a tape.
- amrestore: restore backups, either particular files or complete systems
- amrecover: select from the lists of backups to restore using interactive shell
- amcleanup: Clean up if there is any system failure on the server
- amlabel: Label the backup medium for Amanda
- amcheck: Check the backup systems and files as well as the backup tapes before the backup operation
- amadmin: Backup administrative tasks
- amtape: manage backup tapes, loading and removing them
- amverify: Check the format of tapes
- amverifyrun: Check the tapes from the previous run, specify the configuration directory for the backup
- amrmtape: Remove tape from the Amanda database, used for damaged tapes
- amstatus: show the status of the current Amanda backup operation
Amanda configuration files get automatically created with the installation. A user mentions the directory to use as a holding disk, where backups kept before writing to the tape.
- /etc/amanda: keeps configuration files and subdirectories for different kind of backups to be performed. Each directory contains amanda.conf and disklist file. A user edits them and enters the system's settings. The amanada.conf contains basic configuration parameters like the tape type and logfile, as well as holding file locations. A user can change the commented entires.
The disklist file contains information about a host, file systems and partitions to be backed and dump-type. The possible dump-types defined in amanda.conf. The dump-type parameters include:
priority of the backup
use of compression
comp-root to backup root partitions with compression and low priority
always-full: backup an entire partition with no compression and highest priority - /var/lib/amanda: Keeps log and database files