Backup Strategies

increments.pngThere are many ways to perform backups, in general backup strategies can be categorized as File Level, Hypervisor Level, Guest Operating system Level, or Bare Metal. Often companies with complex infrastructures rely on a combination of these methods to achieve full data protection.

Backup Types

  • Full backup A full backup of a client, also known as a master backup, captures all data selected for protection. For applications and virtual machine infrastructure, all data is included in a full backup, for File-level backup, users are often given the ability to select and deselect data.
  • Differential or Incremental backup is a method of data protection where a system checks the protected client in specified intervals of time and captures changes in the protected data since the last successful backup (of any type).
  • Incremental Forever Backup - With this strategy, a full is run one time, followed by incremental thereafter at the frequency that best suits your environment. The system then synthesizes fulls and differentials locally from the incrementals to ensure quick restores.
  • Synthetic backup A synthetic backup is a full or differential backup that the Unitrends system synthesizes by superimposing the incremental backups on the last successful full backup. It then uses the synthesized backups to create recovery points. After the system creates a synthesized full backup, it uses this backup as a reference point when determining whether the client’s protected data has changed and a differential or incremental backup needs to be run.
  • Selective backup A selective backup is run independently of any full, differential, or incremental backup and captures only the client data that you have selected. Selective backups can be used only for file-level backups.
  • Bare metal backup Entire systems are protected such that the Operating Systems and all settings are able to be recovered onto a new machine. Many vendors only offer Homogeneous bare metal (the systems must be recovered onto the exact same make and model), look for Heterogeneous Bare Metal for the most effective solution.

How to Decide

Determining the method used to perform backups should take into consideration your goals for recovery and control.


  • Your tolerance for data loss is measured in a day or more - Use incremental forever or a weekly full backup with daily differential backups.
  • Your tolerance for data loss is measured in minutes or hours - Use incremental forever or a weekly full backup with daily differential and hourly incremental backups.
  • Your backups need to complete within a few hours during the week but can run continuously on the weekend - Use incremental forever or a weekly full backup with daily differential backups.
  • You need to control when full backups run - If system resources are taxed and you would like to control when a full backup runs, use a weekly full backup with daily differential and/or incremental backups. Keep in mind that synthetic backups are system-side only and do not impact the client or networks.