Physical Identifiers; Logical Banks - Sun Microsystems Sun Fire V440 Diagnostics And Troubleshooting Manual

However, in POST error output (see ), the firmware provides a
CODE EXAMPLE 2-20
memory slot identifier (B0/D1 J0602). Note that B0/D1 identifies the memory slot
and is visible on the circuit board when the DIMM is installed. The label J0602 also
identifies the memory slot, but is not visible unless you remove the DIMM from the
slot.
POST Reference to Physical ID and Logical Bank
CODE EXAMPLE 2-20
1>H/W under test = CPU3 B0/D1 J0602 side 1 (Bank 1), CPU Module C3
Adding to the potential confusion, when configuring system memory, you must also
contend with the separate notion of physical memory banks: DIMMs must be installed
as pairs of the same capacity and type within each physical bank.
The following sections clarify how memory is identified.

Physical Identifiers

Each CPU/memory module's circuit board contains silk-screened labels that
uniquely identify every DIMM on that board. Each label is in this form:
Bx/Dy
where x indicates the physical bank, and y the DIMM number within the bank.
In addition, a "J" number silk-screened on the circuit board uniquely identifies each
DIMM slot. However, this slot number is not readily visible unless the DIMM is
removed from the slot.
If you run POST and it finds a memory error, the error message will include the
physical ID of the failed DIMM and the "J" number of the failed DIMM's slot,
making it easy to determine which parts you need to replace.
Note – To ensure compatibility and maximize system uptime, you should replace
DIMMs in pairs. Treat both DIMMs in a physical bank as one FRU.

Logical Banks

Logical banks reflect the system's internal memory architecture and not the
architecture of the system's field-replaceable units. In the Sun Fire V440 server, each
logical bank spans two physical DIMMs. Since firmware-generated status messages
44 Sun Fire V440 Server Diagnostics and Troubleshooting Guide • July 2003