I/O Subsystem

Indicators on the Memory Board

The memory board contains a green LED to indicate that the board is in service and an amber LED to indicate that the board needs attention. Do not remove a memory board while the green LED is lit.

Dynamic DIMM Sparing

Dynamic DIMM sparing automatically substitutes a spare DIMM in place of an operational DIMM before a high rate of correctable errors leads to an uncorrectable error and loss of data. The cell maintains normal memory operations during the dynamic DIMM sparing process.

In dynamic DIMM sparing, a DIMM, in the last populated slot and next to the last operational DIMM on the channel, must first have been reserved as a spare. Both channels must be populated with identical spare DIMMs in the equivalent slot positions on each channel.

Memory Mirroring

Mirroring is an optional memory addressing mode that provides protection against uncorrectable errors by maintaining two images of memory. With mirroring, all uncorrectable errors, including a complete DIMM or channel failure, will not stop the system.

Mirroring is between the two memory boards within the cell. (Mirroring between memory boards in different cells is not supported.) On detection of a memory failure, the system breaks the mirror and continues operation out of the remaining "good" memory board.

Once the mirror has been broken, you can remove the memory board with the failed DIMM, replace the DIMM, reinstall the memory board, and reestablish mirroring.

I/O Subsystem

The I/O subsystem consists of the I/O riser board, PCIe cards, and the PCIe card carrier.

I/O Riser Board

The I/O riser board contains the following components:

yThree PCIe-to-PCIe x8 switches with each switch supporting two PCIe card slots

ySix PCIe slots which support the following features:

-Two full-length cards slots (slots 1 and 4) and four half-length card slots

-Full-height cards

-25 watts per slot

-PCI Express Gen 1 (2.5 Gbps)

-Hot-plug capability

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NEC A1160 manual Subsystem, Indicators on the Memory Board, Dynamic Dimm Sparing, Memory Mirroring, Riser Board