Top 5 Free Open Source Backup Software
Amanda, or the Advanced Maryland Automatic Network Disk Archiver is an open source computer archiving tool that is able to back up data residing on multiple computers on a network. It uses a client–server model and includes: the backup server and client itself, a tape server, an index server
Amanda was initially developed at the University of Maryland and is released under a BSD-style license. Amanda is available both as a free community edition and fully supported enterprise edition. Amanda runs on almost any Unix or Linux-based systems. Amanda supports Windows systems using Samba or Cygwin. A native Win32 client (with support for open files) is also now available
BackupPC is a free backup software suite with a web-based frontend. The cross-platform server will run on any Linux, Solaris, or UNIX based server. No client is necessary, as the server is itself a client for several protocols that are handled by other services native to the client OS.
For instance, BackupPC incorporates a Server Message Block (SMB) client that can be used to back up network shares of computers running Windows. Paradoxically, under such a setup the BackupPC server can be located behind a NAT'd firewall while the Windows machine operates over a public IP address
cpio can be a very powerful backup tool. Its most important feature is its ability to accept the list of files to be backed up from standard input. It's the only native utility that can do this. This feature can be combined with the use of touch files and the find command to create incremental backups.
cpio is a binary file archiver and a file format. The cpio software utility was meant as a tape archiver that was originally part of PWB/UNIX, and that was also part of UNIX System III and UNIX System V. However, the use of its Research Unix counterpart, tar, and the freely available versions thereof, are widely considered to be a better solution. cpio's use by the RPM Package Manager continues to make cpio an important archive format.
dump is a Unix program used to back up file systems. It operates on blocks, below filesystem abstractions such as files and directories. Dump can back up a file system to a tape or another disk. It is often used across a network by piping its output through bzip2 then SSH. A dump utility first appeared in Version 6 AT&T UNIX.
dump and restore are considered by many to be the most powerful tools in the Unix backup toolbox. dump and restore's differentiating features include being able to back up files without changing their access time and being able to use a mini shell to interactively select the files you want to restore before you begin. dump and restore are relatively sophisticated commands, with simple interfaces whose essential options are the same on most Unix systems. There is a lot of controversy surrounding dump and whether or not it can properly back up an active filesystem
rsync is a software application for Unix systems which synchronizes files and directories from one location to another while minimizing data transfer using delta encoding when appropriate. An important feature of rsync not found in most similar programs/protocols is that the mirroring takes place with only one transmission in each direction. rsync can copy or display directory contents and copy files, optionally using compression and recursion.
In daemon mode, rsync listens to the default TCP port of 873, serving files in the native rsync protocol or via a remote shell such as RSH or SSH. In the latter case, the rsync client executable must be installed on both the local and the remote host.