Lesson 11 – NETWORK DISASTER RECOVERY
Disaster recovery plans Network backup and restoration OVERVIEW
Definition: A document that explores how a Network recovers from a disaster that imperils its data or stops its functioning. DISASTER RECOVERY PLAN
Assessing needs Disaster scenarios Communication Offsite storage Critical components for rebuilding Disaster recovery plan
Plan for contingencies. Define countermeasures. Intimate external auditors about the plan. Inform top management about Network risks. Assessing needs
Calculate time needed to resolve problems. Take input from top management to resume services. Plan with key business considerations. Assessing needs
Disaster scenarios
Network failures: Motherboard failure Disk failure Tape backup drive failure
Disaster scenarios Possible responses: Is a maintenance contract required? Should hardware parts be stocked?
Disaster scenarios Possible responses: Can servers, routers, hubs, and switches be temporarily replaced? Can employees work with replacements/no system?
Board of Directors CEO or President Vice President(s) Head of an affected area Supervisor Employees affected Communication
Protects backup tapes. Should be discussed in the disaster recovery plan. Offsite storage
Computer equipment. Software replacements. Cost estimate of replaced equipment. Critical components for rebuilding
Assessing needs. Acquiring backup media/technologies. Choosing backup strategies. NETWORK BACKUP AND RESTORATION
Is dynamic data stored on the servers? When and how does it change? How much data needs to be backed up? Assessing needs
At what rate is data growing? How much time is available to make the backup? How quickly must restoration take place? Assessing needs
How coherent does backed up data need to be? What is the trade-off between cost and recoverability? How many levels of redundancy are needed? Assessing needs
Acquiring backup media/technologies Factors: Reliability Cost Storage Restoration frequency Backup onto a single medium
Acquiring backup media/technologies
Full backup Incremental backup Differential backup Choosing backup strategies
Rotation strategy: Rebuild system with recent data. Restore files from older tapes. Protect against backup media failure. Protect data from environment failure.
Choosing backup strategies
SUMMARY Disaster recovery plans: Assessing needs Disaster scenarios Communication Offsite storage Critical components for rebuilding
Summary Network backup and restoration: Assessing needs. Acquiring backup media/technologies. Choosing backup strategies.