Bacula

Bacula is an open source, enterprise level computer backup system for heterogeneous networks. It is designed to automate backup tasks that had often required intervention from a systems administrator or computer operator.

Bacula supports Linux, UNIX, Windows, and Mac OS X backup clients, and a range of professional backup devices including tape libraries. Administrators and operators can configure the system via a command line console, GUI or web interface; its back-end is a catalog of information stored by MySQL, PostgreSQL, or SQLite.

Overview

Bacula is a set of computer programs for managing backup, recovery, and verification of computer data across a network—providing a backup solution for mixed operating system environments.

Bacula is the collective work of many developers, including Kern Sibbald, and its current release has been built upon ten years of development. It is open source and available without fees for both commercial and non-commercial application, with respect to the AGPL version 3 license with exceptions to permit linking with OpenSSL and distributing Windows binaries.^[1]

According to project information published on SourceForge, since April 2002, Bacula has over 1.3 million downloads, which makes it the most downloaded open source backup program.

Features

Bacula's features include:

Network options

• TCP/IP - client–server communication uses standard ports and services instead of RPC for NFS, CIFS, etc.; this eases firewall administration and network security
• CRAM-MD5 - configurable client–server authentication
• GZIP/LZO - client-side compression to reduce network bandwidth consumption; this runs separate from hardware compression done by the backup device
• TLS - network communication encryption
• MD5/SHA - verify file integrity
• CRC - verify data block integrity
• PKI - backup data encryption
• NDMP - enterprise version plugin^[2]

Client-options

• POSIX ACL - needed to restore Windows NT ACE's and Samba servers
• Unicode/UTF-8 - cross-platform filenames
• VSS - calls Microsoft's snapshot service
• LVM - pre-script setup for Linux/UNIX snapshot
• LFS - backup files larger than 2GiB
• raw - backup devices without a filesystem

Backup devices

• pooling - allocates backup volumes according to job needs and retention configuration
• spooling - writes backup data to spool until target backup medium is allocated so jobs can continue uninterrupted
• media-spanning - such as spanning tapes
• multi-streaming - write multiple, simultaneous data streams to the same medium
• ANSI & EBCDIC - IBM compatibility
• Barcodes - reading tape barcodes in libraries
• autoloaders - virtually every tape autoloader available (called autochangers in Bacula)
• most tape drives, including DDS, DLT, SDLT, LTO-1-5

Client OS

The client software, executed by a "file daemon" running on a Bacula client, supports many operating systems, ^[3] including:

• Linux - most major distributions, including: CentOS, Debian, Fedora, Gentoo, Mandriva, OpenSUSE, Red Hat and Ubuntu.
• Solaris
• FreeBSD - all released versions
• NetBSD
• Windows (File daemon supported on all 32 and 64 bit Windows OSes)
• Mac OS X
• OpenBSD
• HP-UX
• Tru64
• IRIX

Structure

A Bacula installation contains three kinds of daemons to execute backup and restore functionality:

Director Daemon

manages other daemons, queries and updates catalog, interfaces with operator front-ends, automates backup schedules

Storage Daemon

makes system calls to drive backup media, responds to read/write requests from Director, and receives backup/restore data from file daemon

File Daemon

negotiates client-side communication, encryption and compression, opens file handles to access a client's data

Bacula Console

the control interface from which the user can enter commands to operate Bacula tasks. the console is a command line interface.

Bat (Bacula Administrative Tool) Console

a GUI interface from which the user can enter commands to operate Bacula tasks.

Tray Monitor

is a GUI that can be installed on any desktop to monitor the Bacula operations.

Bweb

a web interface that allows systems management views of all the Bacula backups. It also permits most all operations that can be done with the console.

These daemons can run on independent hosts but typical installations consist of three kinds of Bacula hosts:

Client machines

the machines that contain the files to be backed up

Storage machines

machines that contain the media used to store the backups

Backup Servers

that orchestrate the backup processes

The Director manages everything so is called a "backup server"; the client and storage daemons run as its subordinates and have no direct control of the back up process. While this structure suggests that the three daemons run on three different machines, an equally valid setup is to run all three daemons on the machine that controls the backup process and backup additional machines that have just a file daemon installed. It is also possible to mount remote files and storage resources into the Director's filesystem over SMB or NFS, however, the Bacula developers discourage this in favor of having a File daemon installed on each machine to be backed up. In practice, however, the Director and Storage Daemon are often run on one machine (often referred to as the Bacula Server). The File Daemon is then run on each machine to be backed up (including the Bacula server—because its catalog is dumped as SQL).

Backup data can be stored on various media, including tape, and disk.

Limitations

Bacula stores backup data in an open and documented yet unique volume format; there are Bacula standalone tools to read/write the backup data (bls, bcopy, bscan, bextract), these tools are not compatible with other Unix backup utilities such as tar or dump.

By default, Bacula's differential and incremental backups are based on system time stamps. Consequently, if you move files into an existing directory or move a whole directory into the backup FileSet after a full backup, those files may not be backed up by an incremental save because they may have old dates. You must explicitly update the date/time stamp on all moved files. Bacula versions starting with 3.0 or later support Accurate backup, which is an option that addresses this issue.^[4]

History

Bareos Fork

In 2010, a fork of Bacula was started by contributors that were dissatisfied with the current conduct (by which principal developers allegedly silently ignored contributions), and the change to a closed-source license model for the newly created Enterprise version of Bacula.^[5] Eventually, this fork was made public under the name Bareos in early 2013. It's main goals are to keep the software truly open-source, to ease configuration and introduce new features.^[6] Bacula Systems accused Bareos of copyright violation and filed a lawsuit^[7] against Bareos and a former Bacula community member in early December 2013. The Bareos project in turn considered those accusations as ungrounded FUD,^[8] as the code in question was released under the AGPL.

Further reading

• Storz, Philipp (2013). Bacula. Open Source Press. ISBN 978-3-95539-002-0. 
• Preston, W. Curtis (2007). Backup & Recovery. O'Reilly Media. ISBN 0-596-10246-1. Retrieved 10 May 2010.  Chapter 7 covers Bacula
• Enterprise Networking article
• Server Watch article
• O'Reilly SysAdmin interview article
• Deduplication article

References

External links

• Bacula’s home page
• Linux.com review
• Bacula’s SourceForge Project Page
• Freecode Project Page
• Bareos project page