beautypg.com

1 sas features, 2 sas array limitations, Sas features – Avago Technologies MegaRAID SAS 8204ELP User Manual

Page 26: Sas array limitations

background image

1-10

Overview

Copyright © 2005-2007 by LSI Logic Corporation. All rights reserved.

32-Kbyte nonvolatile random access memory (NVRAM) for storing
RAID system configuration information; the MegaRAID SAS firmware
is stored in flash ROM for easy upgrade.

1.6.1

SAS Features

The following list describes the SAS features:

Provides eight fully independent PHYs

Supports 3.0 Gbit/s SAS data transfers per PHY

Supports SSP to enable communication with other SAS devices

Supports SMP to communicate topology management information

Provides a serial, point-to-point, enterprise-level storage interface

Simplifies cabling between devices

Provides a scalable interface that supports up to 122 devices through
multiple expanders

Note:

The number of devices supported varies depending on the
MegaRAID product. Check the LSI Logic web site
(

http://www.lsi.com

) for specific details about your product.

Supports wide ports consisting of 2, 3, or 4 PHYs within a single
quad port

Supports narrow ports consisting of a single PHY

Transfers data using SCSI information units

1.6.2

SAS Array Limitations

This section describes the array limitations of the MegaRAID 1068-based
SAS RAID controllers. These include limitations such as the number of
physical disks supported, the maximum number of disks per controller,
and the maximum number of virtual disks allowed per controller.

Table 1.1

lists the array limitations for the 1068-based SAS RAID

controllers.