Disk-array enclosure
VNX5700 Hardware Information Guide 67
3U, 15 (3.5-inch) DAE rear view
On the rear, viewing from top to bottom, a 3U, 15 (3.5-inch) disk drive DAE includes the
following hardware components:
◆ Two 6-Gb/s SAS LCCs (A and B)
◆ Two power supply/cooling modules
6-Gb/s SAS LCC
The LCC supports and controls one 6-Gb/s SAS bus and monitors the DAE. A blue
link/activity LED indicates a DAE operating at 6 Gb/s.
The LCCs in a DAE connects to the SPE and other DAEs with 6-Gb/s cables. The cables
connect the LCCs in a system in a daisy-chain (loop) topology.
Internally, each DAE LCC uses protocols to emulate a loop; it connects to the drives in its
enclosure in a point-to-point fashion through a switch. The LCC independently receives
and electrically terminates incoming signals. For traffic from the system’s storage
processors, the LCC switch passes the signal from the input port to the drive being
accessed; the switch then forwards the drive output signal to the port.
Note: If the target drive is not in the LCC’s enclosure, the switch passes the input signal
directly to the output port.
Each LCC independently monitors the environmental status of the entire enclosure, using
a microcomputer-controlled monitor program. The monitor communicates the status to
the storage processor, which polls disk enclosure status. LCC firmware also controls the
SAS PHYs and the disk-module status LEDs.
Disk drive on/activity
(location 5)
Green On Powering and powered up
Blinking, mostly
on
Disk drive is on with I/O activity
Blinking at
constant rate
Disk drive is spinning up or down
normally
Blinking, mostly
off
Disk drive is powered up but not
spinning
Note: This is a normal part of the
spin-up sequence, occurring
during the spin-up delay of a
slot.
— Off Disk is powered down
Table 33 3U, 15 (3.5-inch) DAE and disk drive LEDs (continued)
LED Color State Description
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