Intel 12Gb/s, Руководство пользователя

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12Gb/s Intel® RAID Controllers User Guide 7
SAS Features
The 12Gb/s Intel
®
RAID Controllers support the following SAS features:
•
They provide four fully independent PHYs or eight fully independent PHYs,
depending on the controller.
•
They support 12 Gb/s, 6Gb/s and 3Gb/s SAS data transfers per PHY.
•
They support SMP to communicate topology-management information.
•
They support SSP to enable communication with other SAS devices.
•
They support STP to enable communication with SATA devices through an
attached expander.
•
They provide a serial, point-to-point, enterprise-level storage interface.
•
They simplify cabling between devices.
•
They provide a scalable interface that supports up to 240 devices through the use of
expanders.
Note: The number of devices varies depending on the Intel
®
RAID Controller
product. Check the Intel website, http://www.intel.com, for specific details
about your product.
•
They support wide ports that consist of two, three, or four PHYs within a single
quad port.
•
They support narrow ports consisting of a single PHY.
•
They transfer data by using SCSI information units.
SAS Array Limitations
This section describes the array limitations of the 12Gb/s Intel
®
RAID Controllers. These
limitations include the number of drives supported per controller, the maximum number
of drives per controller, and the maximum number of virtual drives allowed per controller.
The following table lists the array limitations for the 12Gb/s Intel
®
RAID Controllers.
User-specified rebuild rate (specifying the percentage
of system resources to use from 0 percent to 100
percent)
Yes Yes Yes
Nonvolatile random access memory (NVRAM) of 32
KB for storing RAID system configuration information;
the MegaRAID SAS firmware is stored in flash ROM
for easy upgrade.
Yes Yes Yes
Full MegaRAID Software Stack No Yes Yes
iMR Software Stack Yes No No
Feature RS3WC080 RS3DC040 RS3DC080