Data Security

Printer-friendly versionPrinter-friendly version

Every organisation has data and this is one of its most valuable assets.  Most users have experienced the impact of losing data and the problems this creates. It is important that all data is backed up on a regular basis to ensure it can be recovered in the event of a disaster.  The definition of a data backup is the copying of data from one storage medium to another so that it can be restored in the event of the loss of the original.

All organisations should have a documented procedure for data backups.  This should include:

  • What data is backed up
  • How data is backed up
  • How often the data is backed up
  • Where the backup data media is stored
  • A Procedure for testing the validity of data backups
  • Data restore process

Data Backup Media

Data can be backed up using any or all of the following media types




Memory Sticks

  • Cheap
  • Portable
  • Limited capacity
  • Easily lost
  • Requires manual intervention

External Drives

  • Cheap
  • Portable
  • Large Capacity
  • Subject to accidental damage
  • Easily overwritten


  • Cheap
  • Portable
  • Easily lost
  • Easily Damaged
  • CD limited capacity
  • Manual input

Internet File Stores

  • Large capacity
  • No hardware required
  • Uses internet bandwidth
  • Security


  • Large capacity
  • Hardware required
  • Software required
  • Tapes have a limited shelf life

Network Attached Storage

  • Large Capacity
  • Quick restores
  • Hardware required
  • Expensive to setup
  • Large Capacity
  • Quick Restore
  • Off site storage
  • Available anyplace
  • Cost per Gb
  • Good internet connection required
  • Secuirity

Types of Backups

Backup Type




  • Backs up all data
  • Configurable with regards to what data is backed up
  • Can be slow depending on the amount of data


  • Only backs up data that has changed since the last full backup
  • Faster backup
  • Slower data restore as it might require to restore full backup first


  • Faster backup
  • Only backs up data since last incremental
  • Slower to restore data

System State

  • Backs up operating system state
  • Only backs up operating system and system state



All backup media should be stored in a secure location, ideally off site. Backup Software is available to help to automate data backups. This may be built into the operating system.