Amanda for Linux backup
Using a combination of a master backup server and Unix (dump or GNU tar) or Windows (Samba, Cygwin, or a native Windows client), you can use Amanda to back up just about everything on a heterogeneous network. This software can also handle LVM snapshots and hardware snapshots. The master server plans its resources and in general makes sure that it has space and time to do everything it needs to do.
If your data backup needs are small, Amanda may be overkill. Not everyone likes the idea of relying on a central server to manage the process, especially if they're not dealing with tape or another media that they have to worry about filling up and changing out on a regular basis. Some who no longer work with tape libraries have moved on to simpler solutions. Many of those who do work in such an environment find Amanda invaluable thanks to features such as the efficient use of backup media and the ability to write to tape and disk simultaneously.
A popular alternative to Amanda is Bacula. Also free and open source, Bacula requires installing client programs on each machine targeted for backup, which are all controlled through a server that handles the backup rules centrally. Rather than using standard Unix tools for backup, Bacula has its own file format rather than tar although it's not proprietary because the software is open source.
Bacula does routine full and incremental backups, and has better support for setups where you're using multiple servers with their own tape drives. Amanda supports encryption and RAIT (the RAID equivalent for tapes). Bacula offers a scripting language for customizing your backup jobs, and you can use this language to incorporate encryption.
Choosing between these two offerings ultimately comes down to your architecture, requirements, and which software your staff might already know. Those using a central backup server with a single tape drive will likely be happier with Amanda, while if your tape drives are more distributed across your network, Bacula may be a better fit.
While BackupPC lists itself as a high-performance, enterprise-grade backup system, many of its users are using it in smaller scale operations to great effect. This free, open source solution is designed for backing up Linux and "WinXX" laptops and desktops to a file server.
Popular features include the ability to keep historical snapshots of a small company's desktops and laptops for configurable amounts of time, letting users restore their own backups, detecting the presence or absence of a computer (roaming laptops, for example), and warning people when their machines haven't been backed up within a particular time period.
With BackupPC, users can even initiate backups through the Web interface available to both them and the administrators. Each file is stored in an individual tar archive, allowing for easy and fast recovery of single files and groups of files.
BackupPC's downsides include slow performance for large restores, and being impractical for remote use if you have a lot of data. Also, the compressed archives BackupPC creates can't be read with any tool but BackupPC, making you reliant on this specific project for extracting data from the archive. Fortunately, BackupPC is open source, so you can keep a copy of the source code to ensure that you'll never lose access to the program.
Beneath the hood of most Linux backup solutions is rsync. Those who don't feel the need for a special backup tool, commercial or otherwise, often use rsync in combination with scripting to create remote mirrors, rotation schemes, and more.
This tool is also popular for ad hoc backups since it doesn't need any fancy setup. The more your backup needs resemble simple duplication (for example, copying or mirroring the contents of directories, hard drives, or web site content to another location), the easier it is to make rsync do the work, using efficiencies such as only transferring changed file portions over the network, compressing data before transmission, and more along the way.
Commercial Linux backup products
If you prefer commercial Linux backup products, Symantec Corp.'s Veritas NetBackup Enterprise is an enterprise-level client/server suite that offers components for Windows and various Unix and Linux flavors, as well as special support for a variety of virtual environments such as VMware.
NetBackup supports bare-metal restores, and offers dashboards for insight into capacity forecasts, performance trends, compliance, costs and charges for backup and recovery services, and more. If you don't want to build your own reporting or find the options in the other solutions to be unsatisfactory, then a commercial solution such as NetBackup may be more your speed.
Other popular commercial backup solutions for Linux include Symantec's Backup Exec with the Linux/Unix agent and BakBone Software's NetVault.
When looking for a Linux backup tool, you should understand that no backup solution is worthwhile unless you test your ability to restore the data and have a solid data backup and recovery plan. So when you're evaluating potential software, make sure to do so in the context of the bigger picture. Doing so ensures that you really are protected.
This was first published in September 2009