Fault and Error Containment

A Fault in one part of the system cause large voltage swings in the other parts of the system. So it is necessary to prevent from spreading through the system. This is called as containment.

This can be divided into

• Fault Containment Zone (FCZ) and
  
  • A failure of some part of the computer outside an FCZ cannot cause any element inside that FCZ to fail
    
  • Hardware inside the FCZ must be isolated from the outside system.
    
  • Each FCZ should be have independent power supply and its own clock (may be synchronized with the other clocks)
    
  • Typically, the FCZ consists of a whole computer which includes processors, memory I/O and control interfaces.
    
• Error Containment Zone (ECZ)
  
  • Prevent errors from propagating across zone boundaries. This is achived by means of voting redundant outputs.
    
    • Hardware Redundancy
      
    • Software Redundancy
      
    • Time Redundancy
      
    • Information Redundancy