HP VA7410 - Manual (Page 22)

Chapter 4
Peripherals and Accessories
4-112 HP e3000 Business Servers Configuration Guide – Effective 1/04
Information Subject to Change
In a dual controller configuration, both controllers must have the same amount of cache memory as the
contents of NVRAM are mirrored between the two controllers. This mirroring process insures that both
controllers have exactly the same information in the event of a failure. The controller battery maintains
NVRAM contents when normal power is not present. If the battery fails or loses its charge while power is off,
the NVRAM contents are lost on that controller. To protect against data loss, the array power/standby switch
turns off power to the array and the “Shutdown Operation” copies NVRAM contents to the disk drives in slots 1
and 2 of the array. This allows reconstruction of the data in NVRAM if the original data is lost or corrupted.
Note: When upgrading a VA7400 to a VA7410 or a VA7100 to a VA7110 or a VA7410, both DIMMs need to
be the same part number (A6186-60002, for example).
Note: The process of copying the contents of NVRAM to the two recovery disks makes the disk set
independent of its controller. Because all the necessary mapping information is on these disks, it is
possible to install a new controller or move the entire disk set to another controller. The new controller will
determine that it has a new disk set, and the controller will attach itself to those disks.
DIMM Sizes and Cache Sizes
Array Minimum Cache Maximum Cache
VA7100 256-MB/controller 1024-MB/controller
VA7110 1024-MB/controller 2048-MB/controller
VA7410 1024-MB / controller 2048-MB / controller
Configurations of only one size DIMM in controllers are supported (for example, mixing 512-MB and 1024-MB DIMMs in the same controller is not supported).
Slot 1 DIMM (MB) Slot 2 DIMM (MB) Total Memory (MB) VA7100 VA7110 VA7410
256-MB – 256-MB Y N N
256-MB 256-MB 512-MB Y N N
512-MB – 512-MB Y N N
512-MB 512-MB 1024-MB Y Y* Y*
1024-MB – 1024-MB Y Y Y
1024-MB 1024-MB 2048-MB N Y Y
* This is a supported configuration, but new VA7110 controllers will not ship with 512-MB DIMMs.
Battery
Each array controller includes one battery to supply backup power to the DIMMs in the event have a power
failure or if array power is switched off. If power is lost, the BATTERY LED will flash with a 5% duty cycle
while it powers the DIMMs. The battery will maintain a charge for 3.5 days. If the battery loses its charge, or if
it is removed from the controller, the DIMMs have no power and NVRAM contents are lost. A battery should
be replaced when the software indicates a battery has failed.
Early Warning Switch
In a dual controller configuration, the NVRAM contents on both controllers are updated constantly. By
maintaining a mirror image of the NVRAM, the secondary controller can take over immediately if the primary
controller fails. If a dual controller needs to be replaced online, an early warning switch incorporated into the
latch detects when the controller is being removed. Releasing the latch disables communication between
controllers before power is lost to the controller being removed. This prevents corruption of the NVRAM
contents.
Disk Drives
The array must have a minimum of four disk drives installed. Several types of disk drives can be installed in
the array and capacities can be mixed within the array:
• 18-GB Low-Profile Fibre Channel 15,000 rpm (supported, but no longer orderable)
• 36-GB Low-Profile Fibre Channel 10,000 rpm
• 36-GB Low-Profile Fibre Channel 15,000 rpm
• 73-GB Low-Profile Fibre Channel 10,000 rpm
• 73-GB Low-Profile Fibre Channel 15,000 rpm
• 146-GB Low-Profile Fibre Channel 10,000 rpm (VA7410 and VA7110 arrays only)