Disk-array enclosures
General information on front-loading DAEs
Each DAE with front facing drives typically consists of the following components:
- Drive carrier
- Disk drive
- Midplane
- Link control cards (LCCs)
- Power supply/cooling modules
- EMI shielding
Drive carrier
The disk drive carriers are metal and plastic assemblies that provide smooth, reliable contact with the enclosure slot guides and midplane connectors. Each carrier has a handle with a latch and spring clips. The latch holds the disk drive in place to ensure proper connection with the midplane. Disk drive activity/fault LEDs are integrated into the carrier.
Disk drives
Each disk drive consists of one disk drive in a carrier. You can visually distinguish between disk drive types by their different latch and handle mechanisms and by type, capacity, and speed labels on each disk drive. You can add or remove a disk drive while the DAE is powered up, but you should exercise special care when removing disk drives while they are in use. Disk drives are extremely sensitive electronic components.
Midplane
A midplane separates the front-facing disk drives from the rear-facing LCCs and power supply/cooling modules. It distributes power and signals to all components in the enclosure. LCCs, power supply/cooling modules, and disk drives plug directly into the midplane.
Link control cards (LCCs)
An LCC supports, controls, and monitors the DAE, and is the primary interconnect management element. Each LCC includes connectors for input and expansion to downstream devices. An enclosure address (EA) indicator is located on each LCC. Each LCC also includes a bus (loop) identification indicator.
Power supply/cooling modules
The power supply/cooling module integrates independent power supply and blower cooling assemblies into a single module.
Each power supply is an auto-ranging power-factor-corrected, multi-output, off-line converter with its own line cord. The drives and LCC have individual soft-start switches that protect the disk drives and LCC if you install them while the disk enclosure is powered up. A disk or blower with power-related faults will not affect the operation of any other device.
Each power/cooling module has three status LEDs.
EMI shielding
EMI compliance requires a properly installed electromagnetic interference (EMI) shield in front of the DAE disk drives. When installed in cabinets that include a front door, the DAE includes a simple EMI shield. Other installations require a front bezel that has a locking latch and integrated EMI shield. You must remove the bezel/shield to remove and install the disk drive modules.
Disk drive type
2U, 25 (2.5-inch) DAE
The 25 (2.5-inch) disk drive DAE is 2 rack units (U), 3.40 inches, high and includes slots for 25 2.5-inch disk drives. It uses a 12-Gb/s SAS interface for communication between the storage processors (SPs) and the DAE.
Review the following sections for details on the components and LEDs comprising this DAE.
2U, 25-drive DAE front view
On the front, the 2U, 25 disk drive DAE includes the following components:
- Disk drives in 2.5-inch carriers (hot-swappable)
- Status LEDs
Figure 1 shows the location of these components.

Location
|
Description
|
Location
|
Description
|
---|---|---|---|
![]() |
2.5-inch 6-Gb/s SAS drives
|
![]() |
Disk drive fault LED (amber)
|
![]() |
DAE fault LED (amber)
|
![]() |
Disk drive status/activity (blue)
|
![]() |
DAE power status LED (blue)
|
|
Table 2 describes the 2U, 25 (2.5-inch) DAE and disk drive status LEDs.
LED
|
Location
|
Color
|
State
|
Description
|
---|---|---|---|---|
DAE fault
|
![]() |
Blue
|
On
|
No fault has occurred
|
Amber
|
On
|
Fault has occurred
|
||
DAE power
|
![]() |
Blue
|
On
|
Powering and powered up
|
—
|
Off
|
Powered down
|
||
Disk drive fault
|
![]() |
Amber
|
On
|
Fault has occurred
|
—
|
Off
|
No fault has occurred
|
||
Disk drive on/activity
|
![]() |
Blue
|
On
|
Powering and powered up
|
Blinking
|
Disk drive activity
|
2U, 25 (2.5-inch) rear view
On the rear of a 2U, 25 (2.5-inch) DAE are the following components:
- Two 12-Gb/s SAS link control cards (LCC); A (
) and B (
)
- Two power supply/cooling modules; A (
) and B (
)

2U, 25-drive DAE LCC
LCC functions and features
The LCC supports, controls, and monitors the DAE, and is the primary interconnect management element. Each LCC includes connectors for input and output to downstream devices.
The LCCs in a DAE connects to the storage processors and other DAEs. The cables connect the LCCs in a system in a daisy-chain 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.
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.
An enclosure ID, sometimes referred to as the enclosure address (EA), indicator is located on each LCC. Each LCC also includes a bus (back-end port) identification indicator. The SP initializes the bus ID when the operating system is loaded.
12-Gb/s LCC ports, LEDs, and connectors
Each 3U, 15 (3.5-inch) DAE LCC shows the following ports, LEDs, and connectors:

Location
|
Description
|
Location
|
Description
|
---|---|---|---|
![]() |
Ejector latch handles
|
![]() |
LCC power LED
|
![]() |
LCC fault LED
|
![]() |
Enclosure ID display
|
![]() |
LCC management port (RJ-12) (not used)
|
![]() |
12-Gb/s SAS ports
|
![]() |
Back-end (BE) bus ID display
|
![]() |
SAS port status LED
|
LED
|
Location
|
Color
|
State
|
Description
|
---|---|---|---|---|
LCC fault LED
|
![]() |
Amber
|
On
|
Fault within the LCC
|
—
|
Off
|
No fault or powered off
|
||
LCC power LED
|
![]() |
Blue
|
On
|
Powered on and no fault
|
—
|
Off
|
Powered off
|
||
SAS port status LED
|
![]() |
Amber
|
On
|
SAS port faulted
|
Blue
|
On
|
SAS port linked up
|
||
—
|
Off
|
No connector in port
|
2U, 25-drive DAE power supply and cooling module
Power supply and cooling module functions and features
The power supply/cooling modules are located to the left and right of the LCCs. The units integrate independent power supply and two dual-blower cooling assemblies into a single module.
Each power supply is an auto-ranging, power-factor-corrected, multi-output, offline converter with its own line cord. Each supply supports a fully configured DAE and shares load currents with the other supply. The drives and LCCs have individual soft-start switches that protect the disk drives and LCCs if they are installed while the disk enclosure is powered up. The enclosure cooling system includes two dual-blower modules.
Power supply and cooling module connectors and LEDs
Figure 4 shows an example of a 2U, 25-drive DAE AC power supply/cooling module with a power in (recessed) connector (plug) and status LEDs.

Location
|
Description
|
Location
|
Description
|
---|---|---|---|
![]() |
Ejector latch handle
|
![]() |
Power supply/cooling module fault LED
|
![]() |
AC power LED (input)
|
![]() |
Grounding screw
|
![]() |
DC power LED (output)
|
![]() |
LCC B AC power supply power in (recessed plug)
|
LED
|
Location
|
Color
|
State
|
Description
|
---|---|---|---|---|
AC power LED (input)
|
![]() |
Green
|
On
|
AC power on
|
—
|
Off
|
AC power off, verify source power
|
||
DC power LED (output)
|
![]() |
Green
|
On
|
DC power on
|
—
|
Off
|
DC power off, verify source power
|
||
Power supply/cooling module fault LED
|
![]() |
Amber
|
On
|
Fault
|
Blinking
|
During power shutdown and during overvoltage (OVP) and undervoltage protection (UVP) fault
|
|||
—
|
Off
|
No fault or power off
|
3U, 15 (3.5-inch) DAE
The 15 (3.5-inch) disk drive DAE is 3 rack units (U), 5.25 inches, high and includes slots for 15 3.5-inch disk drives. It uses a 12-Gb/s SAS interface for communication between the storage processors (SPs) and the DAE.
Review the following sections for details on the components and LEDs comprising this DAE.
3U, 15-drive DAE Front view
On the front, the 3U, 15 disk drive DAE includes the following components:
- Disk drives in 3.5-inch carriers (hot-swappable)
- Status LEDs
Figure 5 shows the location of these components.

Location
|
Description
|
Location
|
Description
|
---|---|---|---|
![]() |
3.5-inch disk drive carriers that hold 2.5- or 3.5-inch disk drives
|
![]() |
Disk drive fault LED
|
![]() |
DAE fault LED
|
![]() |
Disk drive on/activity LED
|
![]() |
DAE power on LED
|
|
Table 8 describes the 2U, 25 (2.5-inch) DAE and disk drive status LEDs.
LED
|
Location
|
Color
|
State
|
Description
|
---|---|---|---|---|
DAE fault
|
![]() |
Amber
|
On
|
Fault has occurred within DAE
|
DAE power
|
![]() |
Blue
|
On
|
Enclosure power on (main voltage)
|
—
|
Off
|
Enclosure power off
|
||
Disk drive fault
|
![]() |
Amber
|
On
|
Fault has occurred
|
—
|
Off
|
No fault has occurred
|
||
Disk drive on/activity
|
![]() |
Blue
|
On
|
Powering and powered up
|
Blinking
|
Disk drive activity
|
|||
—
|
Off
|
Powered down
|
3U, 15-drive DAE rear view
On the rear, the 3U, 15-drive DAE includes the following components:
- Two 12-Gb/s SAS link control cards (LCC); A (
) and B (
)
- Two power supply/cooling modules; A (
) and B (
)
The 3U, 15-drive DAE rear components are redundantly distributed across two sides, A and B. When viewed from behind, the top two components make up the B-side of the DAE, and the bottom two components make up the A-side.
Figure 6 shows an example of the rear view of a 3U, 15-drive DAE.

3U, 15-drive DAE LCC
Link control card functions and features
The LCC supports, controls, and monitors the DAE, and is the primary interconnect management element. Each LCC includes connectors for input and output to downstream devices.
The LCCs in a DAE connects to the storage processors and other DAEs. The cables connect the LCCs in a system in a daisy-chain 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.
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.
An enclosure ID, sometimes referred to as the enclosure address (EA), indicator is located on each LCC. Each LCC also includes a bus (back-end port) identification indicator. The SP initializes the bus ID when the operating system is loaded.
3U, 15-drive DAE LCC connectors and LEDs
Each 3U, 15 (3.5-inch) DAE LCC shows the following ports, LEDs, and connectors:

Location
|
Description
|
Location
|
Description
|
---|---|---|---|
![]() |
LCC management port (RJ-12) (not used)
|
![]() |
Captive screw
|
![]() |
12-Gb/s SAS ports
|
![]() |
Part number label
|
![]() |
Enclosure ID display
|
![]() |
LCC power LED
|
![]() |
LCC fault LED
|
![]() |
SAS port status LED
|
![]() |
Back-end (BE) bus ID display
|
|
Review Table 12 for the LED descriptions and status meanings.
LED
|
Location
|
Color
|
State
|
Description
|
---|---|---|---|---|
LCC fault LED
|
![]() |
Amber
|
On
|
Fault within the LCC
|
—
|
Off
|
No fault or powered off
|
||
LCC power LED
|
![]() |
Blue
|
On
|
Powered on and no fault
|
—
|
Off
|
Powered off
|
||
SAS port status LED
|
![]() |
Amber
|
On
|
SAS port faulted
|
Blue
|
On
|
SAS port linked up
|
||
—
|
Off
|
No connector in port
|
3U, 15-drive DAE power supply and cooling module
Power supply and cooling module functions and features
The power supply/cooling modules are located above and below the LCCs. The units integrate independent power supply and dual-blower cooling assemblies into a single module.
Each power supply is an auto-ranging, power-factor-corrected, multi-output, offline converter with its own line cord. Each supply supports a fully configured DAE and shares load currents with the other supply. The drives and LCCs have individual soft-start switches that protect the disk drives and LCCs if they are installed while the disk enclosure is powered up. The enclosure cooling system includes two dual-blower modules.
Power supply and cooling module connectors and LEDs
Figure 8 shows an example of the 3U 15 (3.5 inch) disk drive DAE AC power supply/cooling module with a power in (recessed) connector (plug) and status LEDs.

Location
|
Description
|
Location
|
Description
|
---|---|---|---|
![]() |
AC power in (recessed plug) connector
|
![]() |
Power supply fault LED
|
![]() |
Cooling fault LED
|
![]() |
Part number label
|
![]() |
Power supply on LED
|
![]() |
Captive screw
|
Review Table 12 for the LED descriptions and status meanings.
LED
|
Location
|
Color
|
State
|
Description
|
---|---|---|---|---|
Cooling fault
|
![]() |
Amber
|
On
|
Fault, one or both blowers not operating normally
|
—
|
Off
|
No fault, blowers operating normally
|
||
Power supply on
|
![]() |
Green
|
On
|
Power on
|
—
|
Off
|
Power off
|
||
Power supply fault
|
![]() |
Amber
|
On
|
Fault
|
Blinking
|
During power shutdown and during overvoltage and undervoltage protection (OVP/UVP) fault
|
|||
—
|
Off
|
No fault or power off
|
General information on drawer-type DAEs
Each DAE with internal drives typically consists of the following components:
- Drive carrier
- Disk drive
- Link control cards (LCCs)
- Power supply
- Cooling modules
- EMI shielding
- Cable management arms
Drive carrier
The disk drive carriers are metal and plastic assemblies that provide smooth, reliable contact with the enclosure slot guides and midplane connectors. Each carrier has a handle with a latch and spring clips. The latch holds the disk drive in place to ensure proper connection with the midplane. Disk drive activity/fault LEDs are integrated into the carrier.
Disk drives
Each disk drive consists of one disk drive in a carrier. You can visually distinguish between disk drive types by their different latch and handle mechanisms and by type, capacity, and speed labels on each disk drive. You can add or remove a disk drive while the DAE is powered up, but you should exercise special care when removing disk drives while they are in use. Disk drives are extremely sensitive electronic components.
Link control cards (LCCs)
An LCC supports, controls, and monitors the DAE, and is the primary interconnect management element. Each LCC includes connectors for input and expansion to downstream devices. An enclosure address (EA) indicator and bus (loop) identification indicator is located on one LCC of each DAE.
Power supply
The power supplies and cooling modules or fans are separated. The power supplies are located on the rear. The power supply module has an orange knob used for removing and installing the power supply module from the DAE .
Cooling modules (Fans)
The cooling modules or fans are separate from the power supply modules. The cooling modules or fans are located on the front and middle of the drawer-type DAEs, depending on DAE type. The cooling modules or fans can only be installed/removed by sliding the DAE forward. You access the cooling modules or fans from inside the DAE.
EMI shielding
EMI compliance requires a properly installed electromagnetic interference (EMI) shield in front of the DAE disk drives. When installed in cabinets that include a front door, the DAE includes a simple EMI shield. Other installations require a front bezel that has a locking latch and integrated EMI shield. You must remove the bezel/shield to remove and install the disk drive modules.
Cable management arms
Locking Scissor-type cable management arms attach to the rear of the drawer-type DAEs to provide easy cable management for the power cords and SAS cables that attach to the rear ports of the DAE. The cable management arms extend to an open position when the unlocked DAE is pulled forward in the cabinet and retract to a closed position when the DAE is pushed back into the cabinet.
3U, 80 (2.5-inch) DAE
The 80 (2.5-inch) disk drive DAE is 3 rack units (U), 3.4 inches (8.64 cm) high, and includes slots for 80 2.5-inch disk drives. It uses a 12-Gb/s SAS interface for communication between the storage processors (SPs) and the DAE.
Review the following sections for details on the components and LEDs comprising this DAE.
3U, 80-drive DAE top view
Component overview
The 3U, 80-drive DAE includes the following internal components:
- Disk drives in 2.5-inch carriers (hot-swappable) (
)
- 10 redundant cooling modules
- Five in the front of the system, labeled 0-4 (
)
- Five at the rear of the system, labeled 5-9 (
)
- Five in the front of the system, labeled 0-4 (
The disk drive slots and cooling modules on an 80-drive DAE are located inside the enclosure. To access the disk drives, release and pull the enclosure out of the cabinet. The enclosure slides out of the cabinet far enough for you to access its internal components, and then locks on the rails in the service position so that you cannot pull it out any farther.

Disk drive LEDs

LED
|
Location
|
Color
|
State
|
Description
|
---|---|---|---|---|
Disk drive on/activity
|
![]() |
Blue
|
On
|
Powering and powered up
|
Blinking
|
Disk drive activity
|
|||
Disk drive fault
|
![]() |
Amber
|
On
|
Fault has occurred
|
-
|
Off
|
No fault has occurred
|
Cooling module LEDs
Cooling modules contain only one LED, to indicate that the part has faulted.

3U, 80-drive DAE front view
There is only one component accessible from the front of the 3U 80-drive DAE, the system status card (SSC).

LED
|
Location
|
Color
|
State
|
Description
|
---|---|---|---|---|
System status card fault LED
|
![]() |
Amber
|
On
|
Fault within the system status card
|
-
|
Off
|
No fault
|
||
System fault LED
|
![]() |
Amber
|
On
|
Component within the system (disk, fan LCC, power supply) has faulted
|
-
|
Off
|
No fault
|
||
System status card power LED
|
![]() |
Blue
|
On
|
Powered on and no fault
|
-
|
Off
|
Powered off
|
3U, 80-drive DAE rear view
The following components are accessible from the rear of the 3U, 80-drive DAE:
- Two 12-Gb/s SAS link control cards (LCC); A (
) and B (
)
- Four power supplies (
)
The 3U, 80-drive DAE rear components are redundantly distributed across two sides, A and B. When viewed from behind, the right half of the system makes up the A-side of the DAE, and the left half of the system makes up the B-side.

3U, 80-drive DAE LCC
Link control card functions and features
The LCC supports, controls, and monitors the DAE, and is the primary interconnect management element. Each LCC includes connectors for input and output to downstream devices.
The LCCs in a DAE connect to the storage processors and other DAEs. The cables connect the LCCs in a system in a daisy chain 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.
Each LCC has four ports marked AA/A and BB/B. The A and B ports are used when connecting (A) or expanding (B) using x4 lane cables. The AA/A and BB/B ports are both used when connecting (AA/A) or expanding (BB/B) using x8 lane cabling.
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.
An enclosure ID, sometimes referred to as the enclosure address (EA), indicator is located on each LCC. Each LCC also includes a bus (back-end port) identification indicator. The SP initializes the bus ID when the operating system is loaded.
|
Note:
Some LCCs may not have the enclosure ID display (
![]() ![]() |
3U, 80-drive DAE LCC connectors and LEDs
Each 3U, 80-drive DAE LCC contains the following ports, LEDs, and connectors:

Location
|
Description
|
---|---|
![]() |
12-Gb/s mini SAS ports
|
![]() |
Mini SAS port status LED
|
![]() |
Enclosure ID display
a
|
![]() |
LCC fault LED
|
![]() |
LCC power LED
|
![]() |
Back-end (BE) bus ID display
a
|
![]() |
LCC management port (RJ-12) (not used)
|
LED
|
Location
|
Color
|
State
|
Description
|
---|---|---|---|---|
Mini SAS port status LED
|
![]() |
Blue
|
On
|
SAS port linked up
|
Green
|
On
|
Powered on
|
||
-
|
Off
|
No connector in port
|
||
LCC fault LED
|
![]() |
Amber
|
On
|
Fault within the LCC
|
-
|
Off
|
No fault or powered off
|
||
LCC power LED
|
![]() |
Green
|
On
|
Powered on and no fault
|
-
|
Off
|
Powered off
|
3U, 80-drive DAE power supply
Power supply functions and features
The power supplies are located above the LCCs.
Each power supply is an auto-ranging, power-factor-corrected, multi-output, offline converter with its own line cord. Each supply supports a fully configured DAE and shares load currents with the other supply. The drives and LCCs have individual soft-start switches that protect the disk drives and LCCs if they are installed while the disk enclosure is powered up.
Power supply components and LEDs

Location
|
Description
|
---|---|
![]() |
AC power in (recessed plug) connector
|
![]() |
Release lever
|
![]() |
Retaining bail
|
![]() |
Power supply fault LED
|
![]() |
AC output LED
|
![]() |
AC input LED
|
LED
|
Location
|
Color
|
State
|
Description
|
---|---|---|---|---|
Power supply fault
|
![]() |
Amber
|
On
|
Fault
|
-
|
Off
|
No fault or power off
|
||
AC power LED (input)
|
![]() |
Green
|
On
|
Power on
|
-
|
Off
|
Power off, verify source power
|
||
AC output LED
|
![]() |
Green
|
On
|
Power on
|
-
|
Off
|
Power off, verify source power
|