As defined per default, communication between output folders and destination folders is normally carried out through the transfer protocol TCP (port 873) – provided that a running rsync folder already exists. Access via an unencrypted remote shell (RSH) or an encrypted secure shell (SSH) should not pose any problems. rsync can operate on all conventional Unix operating systems, and due to Cygwin – a Linux-inspired software interface – it can also run on Windows. Furthermore, there are many different synchronization programs for Mac OS X, Windows, and Linux that draw on the rsync protocol. The software, rsnapshot, allows users to create complete, multilevel backups. It relies on rsync in its copying tasks and additionally creates hard links of all copied files that don’t take up any physical memory space.
The destination directory where the backup copy is to be stored can be located on the same computer or on an external storage device. Different hardware may be needed for this, depending on the size of the data. In some cases, a portable hard drive may suffice, while other times an entirely separate server may be required (e.g. when a network mirror is to be created). Thanks to its quick and compressed data transfer, rsync is especially well suited for synchronizing data with servers or devices with a weak data connection. Transferring between two computers at a data center is also a plausible application for rsync’s use. The following aspects comprise backups with rsync:
- No daily maintenance work required
- Compressed data transfer in network
- Possible bandwidth limitation of backup procedure
- Secure transfer via SSH connection
- Seamless transfer of large data volume
- Quick restoring from backups