PRIMECLUSTER Global Disk Services Configuration and Administration Guide 4.1 (Solaris(TM) Operating System)

1.1 GDS Features

GDS is volume management software that improves the availability and manageability of disk-stored data. GDS protects disk data from hardware failures and operational mistakes and supports the management of disk units.

GDS has the following functions, which are closely related:

• To improve availability of disk data

• To improve manageability of disk data

GDS's mirroring function protects data from hardware failures by maintaining replicas of disk data on multiple disks. This allows users to continue to access disk data without stopping the application in the event of unexpected trouble.

[Figure: Disk Mirroring]

GDS allows users to integrate management of all disk units connected to a Solaris OS server. In a PRIMECLUSTER system, GDS also allows users to integrate management of disk units that are shared by multiple servers in a SAN (Storage Area Network) environment as well as local disk units that are connected to specific servers.

[Figure: SAN (Storage Area Network)]

Multiple servers can be connected to multiple disk units in a SAN environment. Disk-stored data can be accessed from those servers. This allows simultaneous access to file systems or databases and improves the efficiency of data duplication between the servers and backup procedures. On the other hand, it also carries the risk of data damage, as multiple servers will compete to access the shared disk. Therefore, volume management functions suitable for the SAN environment are essential.

Since GDS's management function is suitable for a SAN environment, advanced system operation for disk management can be performed with ease.

The user-friendly functions simplify management, and at the same time, prevent data corruption by operational mistakes.

[Figure: Access Control Mechanism in a SAN Environment]