Enclosures

Enclosures are rack-mounted hardware that contain several components of the system. Enclosures can be used to extend the capacity of the system. The term enclosure is also used to describe the hardware and other parts that are plugged into the enclosure.

The system has two different types of enclosures: control enclosures and expansion enclosures. A control enclosure manages your storage systems, communicates with the host, and manages interfaces. In addition, a control enclosure can have multiple attached expansion enclosures, which expand the available capacity of the existing control enclosure. SAN Volume Controller 2145-DH8 and 2145-SV1 control enclosures support multiple attached expansion enclosures. However, 2145-SV2 and 2145-SA2 systems do not support expansion enclosures. On each SAS chain, the systems can support up to a SAS chain weight of 10. Each 5U expansion enclosure adds a value of 2.5 to the SAS chain weight. Each 2U expansion enclosure adds a value of 1 to the SAS chain weight. For example, each of the following expansion enclosure configurations has a total SAS weight of 10:

Four 5U enclosures per SAS chain
Ten 2U expansion enclosures per SAS chain
Two 5U expansion enclosures and five 2U expansion enclosures per SAS chain

For information about connecting the nodes in the I/O group to 2U expansion enclosures, see Connecting the optional 2U SAS expansion enclosures to the 2145-DH8.

Enclosure objects report the connectivity of the enclosure. Each expansion enclosure is assigned a unique ID. It is possible to change the enclosure ID later.