Hardware User Guide

11 12Gb/s Intel® RAID Controllers User Guide
• They support the internal SAS Sideband signal SFF-8485 (SGPIO) interface.
Note: LED signals indicate an error condition or drive activity. The MegaRAID controllers
support different blink patterns for these LEDs, depending on the user configuration and
storage enclosure. For information about the LED blink patterns, contact your storage
enclosure manufacturer.
Flexibility Features
These features increase the flexibility of the RAID controllers:
• They support a Flash ROM interface, a nonvolatile static RAM (NVSRAM)
interface, and a pipelined synchronous burst SRAM (PSBRAM) interface.
• They offer a flexible programming interface to tune I/O performance.
• They permit mixed connections to SAS targets or SATA III targets.
• They leverage compatible connectors for SAS connections and SATA III
connections.
• They permit grouping of up to four PHYs in a single quad port to form a wide port.
• They permit programming of the World Wide Name.
Drive Roaming
Drive roaming occurs when the drives are changed to different ports on the same
controller. When the drives are placed on different channels, the controller detects the
RAID configuration from the configuration data on the drives.
Configuration data is saved in both the NVRAM on the RAID controller and on the drives
attached to the controller. This action maintains the integrity of the data on each drive,
even if the drives have changed their physical device ID.
Note: If you move a drive that is being rebuilt, the rebuild operation restarts; it does not resume
from the stopping point.
Follow these steps to use the drive roaming feature:
1. Turn off the power to the server and all drives, enclosures, and system components.
Disconnect the power cords from the system.
2. Open the host system by following the instructions in the host system technical
documentation.
3. Move the drives to different positions on the backplane to change the targets.
4. Determine the SAS target requirements.
5. Perform a safety check.
a. Make sure that the drives are inserted correctly.
b. Close the cabinet of the host system.