Additional Resources; Installed Documentation - Red Hat ENTERPRISE LINUX 3 - INTRODUCTION TO SYSTEM ADMINISTRATION Administration Manual

176 Chapter 8. Planning for Disaster
8.4.2.4. The Advanced Maryland Automatic Network Disk Archiver (AMANDA)
AMANDA is a client/server based backup application produced by the University of Maryland. By
having a client/server architecture, a single backup server (normally a fairly powerful system with
a great deal of free space on fast disks and configured with the desired backup device) can back up
many client systems, which need nothing more than the AMANDA client software.
This approach to backups makes a great deal of sense, as it concentrates those resources needed for
backups in one system, instead of requiring additional hardware for every system requiring backup
services. AMANDA's design also serves to centralize the administration of backups, making the sys-
tem administrator's life that much easier.
The AMANDA server manages a pool of backup media and rotates usage through the pool in order
to ensure that all backups are retained for the administrator-dictated retention period. All media is
pre-formatted with data that allows AMANDA to detect whether the proper media is available or not.
In addition, AMANDA can be interfaced with robotic media changing units, making it possible to
completely automate backups.
AMANDA can use either or to do the actual backups (although under Red Hat Enterprise
tar dump
Linux using is preferable, due to the issues with raised in Section 8.4.2.3 / :
tar dump dump restore
Not Recommended for Mounted File Systems!). As such, AMANDA backups do not require
AMANDA in order to restore files — a decided plus.
In operation, AMANDA is normally scheduled to run once a day during the data center's backup win-
dow. The AMANDA server connects to the client systems and directs the clients to produce estimated
sizes of the backups to be done. Once all the estimates are available, the server constructs a schedule,
automatically determining the order in which systems are to be backed up.
Once the backups actually start, the data is sent over the network from the client to the server, where it
is stored on a holding disk. Once a backup is complete, the server starts writing it out from the holding
disk to the backup media. At the same time, other clients are sending their backups to the server for
storage on the holding disk. This results in a continuous stream of data available for writing to the
backup media. As backups are written to the backup media, they are deleted from the server's holding
disk.
Once all backups have been completed, the system administrator is emailed a report outlining the
status of the backups, making review easy and fast.
Should it be necessary to restore data, AMANDA contains a utility program that allows the operator
to identify the file system, date, and file name(s). Once this is done, AMANDA identifies the correct
backup media and then locates and restores the desired data. As stated earlier, AMANDA's design
also makes it possible to restore data even without AMANDA's assistance, although identification of
the correct media would be a slower, manual process.
This section has only touched upon the most basic AMANDA concepts. To do more research on
AMANDA, start with the man page.
amanda(8)

8.5. Additional Resources

This section includes various resources that can be used to learn more about disaster recovery and the
Red Hat Enterprise Linux-specific subject matter discussed in this chapter.

8.5.1. Installed Documentation

The following resources are installed in the course of a typical Red Hat Enterprise Linux installation
and can help you learn more about the subject matter discussed in this chapter.