IBM ServeRAID M5025, User Manual

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1-10 Overview
1.6.1 SAS Features
The following list describes the SAS features of the ServeRAID M5025
controller:

Provides eight fully independent PHYs

Supports 6.0 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 248 devices
through the use of expanders

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 ServeRAID M5025
SAS/SATA controller. 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 1.2 lists the array limitations for the ServeRAID M5025 controller.
Table 1.2 ServeRAID M5025 SAS/SATA Controller Array
Limitations
Specification
ServeRAID M5025
SAS/SATA Controller
Maximum virtual disks per controller 64
Maximum arrays per controller 16
Maximum virtual disks per array 16
Maximum physical devices per array 32
Maximum physical devices per controller 16