You can install a single storage array by using a split-bus configuration. You can install two storage arrays by using a single-bus configuration.
To use a single storage array in a Sun Cluster environment, you must use the split-bus configuration.
As Figure 3–24 shows, the split-bus configuration requires that the storage array contain two Environmental Service Modules (ESM). Each ESM is connected to two nodes. Each ESM controls half the disks in the storage array and the data is mirrored by using a volume manager.
As Figure 3–25 shows, the single-bus configuration requires two storage arrays that each contain a single Environmental Service Module (ESM). The ESM controls all disks on the storage array in which it is installed and the volume manager implements mirroring between the two storage arrays. Each ESM must be connected to two nodes.
Ensure that the entire bus length that is connected to the storage array is less than 12 m. The bus length includes the cables from the ESM to the host adapter. See the documentation that shipped with your hardware for internal bus length.