You are currently viewing CISSP Notes: Full Backups, Differential Backups & Incremental Backups

CISSP Notes: Full Backups, Differential Backups & Incremental Backups

Full Backups

  • A full data backup of all the data from a device
  • Archive bit changed from 1 to 0 once the data has been backed up

Differential Backups

  • A backup of files that have changed since the last full backup
  • Only files with the archive bit set to 1 will be backed up
  • Differential backups do not reset the archive bit to 0
  • Differential backup are quicker to restore

Differential Backup Example

Network Wizkid Corp performs a full backup of their servers every Sunday at 1:00 AM followed by differential backups at the same time every other day. If their server fails on Wednesday and requires restoration at 12:00 PM, Network Wizkid Corp will be required to restore from the last full backup and the last differential backup only (Total of 2 backups = ((Differential Backup) Wednesday)) + ((Full Backup) Sunday)).

Incremental Backups

  • A backup of files that have changed since the last full full backup OR since the last incremental backup
  • Only files with the archive bit set to 1 will be backed up
  • Archive bit changed from 1 to 0 once the backup is complete
  • Incremental backup are longer to restore

Incremental Backup Example

Network Wizkid Corp performs a full backup of their servers every Sunday at 1:00 AM followed by incremental backups at the same time every other day. If their server fails on Wednesday and requires restoration at 12:00 PM, Network Wizkid Corp will be required to restore from the last full backup and the last three incremental backups (Total of 4 backups = ((Incremental Backups) Monday, Tuesday, Wednesday) + ((Full Backup) Sunday)).

iwiizkiid

Kelvin is a Cyber Security professional with years and experience working with organisations in different verticals, both large and small. He enjoys contributing to the Network Wizkid knowledge base and he also creates technical content. Kelvin enjoys learning new things and often does this by working on achieving new technical certifications. He holds many professional certifications and academically, he has achieved a Bachelors and Master's degree in both Computer Networks and Cyber Security.

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