High Availability Using Fault Tolerance in the SAN

Mark Fleming, Senior Software Engineer, IBM

Availability is typically expressed as a percentage of uptime in a given year. Modern SANs have developed numerous methods using hardware and software fault tolerance to assure high availability of storage to customers. From the storage controller through the paths to the end servers, numerous methods exist to ensure continued access to storage in the event of faults and hardware/software failures.

Learning Objectives:

• Understand how Fault Tolerance and High Availability are related.
  
• Understand availability methods from the storage to the server.
  
• Learn common single points of failure, and hear stories from the field.