Avago Technologies MegaRAID SAS 8204ELP - Manual (Page 19)

Configuration Scenarios 1-5
Copyright © 2007 by LSI Corporation. All rights reserved.
The SAS RAID controllers support the SAS protocol as described in the
Serial Attached SCSI Standard, version 1.1. The controllers also support
the Serial ATA II (SATA II) protocol defined by the Serial ATA
Specification, Version 1.0a and the Serial ATAII; Extension to the Serial
ATA Specification, Version 1.1. SATA II is an extension to SATA 1.0a. In
addition, the SAS RAID controllers support the following SATA II features:
•
3 Gbit/s SATA II
•
Staggered spin-up
•
Hot plug
•
Native command queuing
•
Activity and fault indicators for each PHY
•
Port selector (for dual-port drives)
Each port on the SAS controllers supports SAS devices, SATA II devices,
or both using SSP, SMP, STP, and SATA II. SSP enables communication
with other SAS devices. SATA II enables the SAS controllers to
communicate with other SATA II devices.
1.4 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 is like the internal
SATA II configurations, but with high-end disks. This is more suitable
for low-range to midrange servers.
•
High-end external SAS/SATA II configurations: This configuration
is for both internal and external connectivity, using SATA II drives,
SAS drives, or both. External enclosure management is supported