Lenovo ThinkServer RD230, Software User'S Manual

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1-6 Overview
UEFI 2.0 provides MegaRAID customers with expanded platform
support. The MegaRAID UEFI 2.0 driver, a boot service device driver,
handles block IO requests and SCSI pass-through commands (SPT),
and offers the ability to launch pre-boot MegaRAID management
applications through a driver configuration protocol (DCP). The UEFI
driver also supports driver diagnostic protocol, which allows
administrators to access pre-boot diagnostics.
1.7 Configuration Scenarios
There are three main scenarios in which you can use the SAS RAID
controllers:
•
Low-end, internal SATA II configurations: In this configuration, use
the RAID controller as a high-end SATA II compatible controller that
connects up to eight disks either directly or through a port expander.
This configuration is mostly for low-end or entry servers. Enclosure
management is provided through out-of-band I
2
C bus. Side bands of
both types of internal SAS connectors support the SFF-8485
(SGPIO) interface.
•
Midrange internal SAS configurations: This configuration is like
the internal SATA II configurations, but with high-end disks. This
configuration is more suitable for low-range to midrange servers.
•
High-end external SAS/SATA II configurations: This configuration
is for both internal connectivity and external connectivity, using SATA
II drives, SAS drives, or both. External enclosure management is
supported through in-band, SCSI-enclosed storage. The
configuration must support STP and SMP.
Figure 1.1 shows a direct-connect configuration. The Inter-IC (I
2
C)
interface communicates with peripherals. The external memory bus
provides a 32-bit memory bus, parity checking, and chip select signals
for pipelined synchronous burst static random access memory
(PSBRAM), nonvolatile static random access memory (NVSRAM), and
Flash ROM.
Note: The external memory bus is 32-bit for the SAS 8704ELP
and the SAS 8708ELP, and 64-bit for the SAS 8708EM2,
the SAS 8880EM2, and the SAS 8888ELP.