BackupPC is an Open Source software application that runs under Linux on a standard PC computer platform (the Host Machine). The Host Machine is configured with adequate disk storage to house the information being backed up (the Backup Volume). BackupPC provides outstanding network wide backup functionality.
BackupPC can be configured to back up a Windows share (the Target Folder) on each machine (the Target Machine) in a network where backup is required.
The Backup Process runs with share rights which are set either on the individual Target Machine or on an Active Directory Domain user with rights to access the Target Folders. For example the Target Folders on a machine are shared giving ‘BackupPC’ access rights.
Each Target Machine is added to BackupPC’s task list with the following information:
- Network host address for the Target machine;
- Folder paths of the Target Folders
- Clearly with a DHCP network the network host address is based on each user’s host name so it is important that network DNS is functioning.
Full Backups
In a full backup all the files in the Target Set are backed up to the Backup Volume on the BackupPC Host Machine and may optionally be replicated to removable media and taken off site.
The following options can be set for the full backup process.
Full Period
The Full Period sets the period between Full Backups (e.g. 6.97 days for a weekly period).
Full Keep Count
BackupPC always keeps the Full Keep Count number of backups in a full backup cycle.
For example, setting Full Keep Count to 3 will mean that there will always be 3 full backups from which a file or files may be restored.
Full Age Max and Min
The maximum and minimum ages of Full Backups can be set using the Full Age Max and Full Age Min settings.
Pooling Backup System
BackupPC uses a pooling system or single instance store for its backup data sets. This means that if a file hasn’t changed between backups BackupPC does not back it up again. It simply links the reference in the backup index to a previous identical instance of the file. It uses the powerful MD5 hashing algorithm to determine file identities so as to immediately detect changed files and back them up again. This way if a file is corrupted the uncorrupted version will not be inadvertently overwritten, a failing of most backup systems. As a result of this pooling system BackupPC is extremely conservative in its use of disk space which makes it possible to conveniently retain multiple copies of the backup.