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

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

Acquiring backup media/technologies

Acquiring backup media/technologies

Full backup

Incremental backup

Differential backup

Choosing backup strategies

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.