PRIMECLUSTER Global Disk Services Configuration and Administration Guide 4.1 (Linux)

1.3.4 Single System Image Environment

In a SAN environment, a disk unit can be accessed from multiple servers. GDS provides a single system image environment, in which a cluster system with multiple servers (also referred to as nodes) appears as one system to the users or application.
This single system image environment can be utilized as explained below.

• Application programs sharing the same disk can lookup disks and volumes using the same name from all nodes.
• Application programs can access the disk simultaneously from all nodes. For details, see "Note."
• Application programs can perform operations from all nodes, such as changing the configuration on objects (such as disks and volumes). Changes are reflected on all nodes.

   

[Figure: Single System Image Environment]

 

Access Exclusion Control
When the same block is accessed simultaneously, data consistency is maintained by access exclusion control performed by the application that runs on multiple nodes simultaneously.