HP StorageWorks 500 Modular Smart Array - Manual (Page 53)

Hardware Options Installation
HP StorageWorks Modular Smart Array 500 System User Guide 3-9
HP StorageWorks Modular Smart Array 500 Controller
Option
The system ships with one MSA500 controller. To provide redundancy and
maximize storage system uptime, install a second Smart Array controller.
Observe the following guidelines:
• If a controller has more than one cache DIMM, be sure that both DIMMs have
the same memory capacity.
• Always upgrade the cache in both controllers in a system with redundant
controllers.
• In a system with a redundant controller, be sure that both controllers have the
same number of DIMMs and that all DIMMs have the same memory capacity.
• To configure a MSA500 system for controller redundancy, both controllers must
execute the same version of firmware. If the controllers have different firmware
versions, the system responds as follows:
— In a hot-plug addition of the second controller, the system clones the
firmware version of the active controller onto the second controller. After the
second controller is reset, the controllers become redundant.
— In a non-hot-plug addition of the second controller, the system examines the
firmware versions of both controllers at power up and clones the most recent
version from one controller to the other controller.
For more information about upgrading firmware, refer to Chapter 4, “Configuration
and Utilities.”