These notes pertain to a multiple-level backup system. We are referring to a backup system that uses local storage (usually an internal or external hard disk) to back up server data in conjunction with an on-line backup service for off-site storage.

• Typical Scenario
  • Software RAID 5 for primary storage
  • Separate hard drive for backups
  • Hard drive only mounted during backup

• Level 1 Backup
  • Uses local hard disk
    • Fast backups
    • Minimal 'backup window' (time) required
    • Fast and convenient restores
    • Disaster recovery

• Level 2 Backup
  • Uses on-line backup service
    • Slower than level 1
    • Off-site storage
    • No hardware required