Lenovo ServeRAID M1115, Руководство пользователя, Страница: 23 / 69

1-6 Overview
1.5 Integrated MegaRAID Mode
You can run this ServeRAID SAS/SATA controller in integrated
MegaRAID (iMR) mode. Integrated MegaRAID is a highly integrated,
low-cost RAID solution made possible by Fusion-MPT™ architecture. It
is a processor-based, hardware RAID solution designed for system
environments requiring redundancy and high availability where a full-
featured RAID implementation is not desired or might be cost prohibitive.
iMR mode supports RAID levels 0, 1, 5, 10, and 50. RAID 5 and 50 are
supported with an optional upgrade key.
The major advantage of Integrated MegaRAID is that iMR provides RAID
at the processor level, so it does not burden the CPU, which allows for
more efficient operation.
1.6 Configuration Scenarios
There are two main scenarios in which you can use this ServeRAID
controller:
•
Low-end, internal SATA configuration: In this configuration, use
the ServeRAID controller as a high-end SATA compatible controller
that connects to several SATA disks. This type of 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 configuration: This is like the internal
SATA configuration, but with high-end disks. This type of
configuration is more suitable for low-range to midrange servers.
The following figure 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.