Bacula is a set of computer programs that permits you (or the system administrator) to manage backup, recovery, and verification of computer data across a network of computers of different kinds. In technical terms, it is a network Client/Server based backup program. Bacula is relatively easy to use and efficient, while offering many advanced storage management features that make it easy to find and recover lost or damaged files. Due to its modular design, Bacula is scalable from small single computer systems to systems consisting of hundreds of computers located over a large network.
Bacula Director service consists of the program that supervises all the backup, restore, verify and archive operations. The system administrator uses the Bacula Director to schedule backups and to recover files. For more details see the Director Services Daemon Design Document in the Bacula Developer's Guild. The Director runs as a daemon or a service (i.e. in the background).
Bacula Console services is the program that allows the administrator or user to communicate with the Bacula Director (see above). Currently, the Bacula Console is available in two versions. The first and simplest is to run the Console program in a shell window (i.e. TTY interface). Most system administrators will find this completely adequate. The second version is a Qt 4.2 GUI interface named bat that has more features than the bconsole program.
Bacula File services (or Client program) is the software program that is installed on the machine to be backed up. It is specific to the operating system on which it runs and is responsible for providing the file attributes and data when requested by the Director. The File services are also responsible for the file system dependent part of restoring the file attributes and data during a recovery operation. For more details see the File Services Daemon Design Document in the Bacula Developer's Guide. This program runs as a daemon on the machine to be backed up, and in some of the documentation, the File daemon is referred to as the Client (for example in Bacula's configuration file). In addition to Unix/Linux File daemons, there is a Windows File daemon (normally distributed in binary format). The Windows File daemon runs on all currently known Windows versions (2K, 2003, XP, and Vista).
Bacula Storage services consist of the software programs that perform the storage and recovery of the file attributes and data to the physical backup media or volumes. In other words, the Storage daemon is responsible for reading and writing your tapes (or other storage media, e.g. files). For more details see the Storage Services Daemon Design Document in the Bacula Developer's Guide. The Storage services runs as a daemon on the machine that has the backup device (usually a tape drive).
Catalog services are comprised of the software programs responsible for maintaining the file indexes and volume databases for all files backed up. The Catalog services permit the System Administrator or user to quickly locate and restore any desired file. The Catalog services sets Bacula apart from simple backup programs like tar and bru, because the catalog maintains a record of all Volumes used, all Jobs run, and all Files saved, permitting efficicient restoration and Volume management. Bacula currently supports three different databases, MySQL, PostgreSQL, and SQLite3, one of which must be chosen when building Bacula.