Did some digging in old files... Not sure how applicable it is to variations of the shelves over time.
The VNX storage capacity can be expanded with three DAE options. The first option is a 2U DAE
which can contain up to 25, 2.5 inch, 6 Gb SAS drives. The second option is a 3U DAE which can
contain up to 15, 3.5 inch, 6 Gb SAS drives. Both of these DAEs may be installed in the same
array and both offer high-efficiency power supplies, drive spin down, adaptive cooling, and
ambient temperature reporting. Each DAE can contain a mixture of all drive types (Flash, SAS,
and NL SAS).
The Disk Array Enclosures (DAE) are highly available, high performance, storage system
components that communicate with the disk drives via a 6 Gb Serial Attached SCSI (SAS)
interconnect interface. A DAE connects to another DAE or an SPE and is managed by the
storage system software.
The third DAE option is a 4U DAE which can contain up to 60, 2.5-inch or 3.5-inch 6 Gb SAS
drives. This DAE, like the others, offers high-efficiency power supplies, drive spin down,
adaptive cooling, and ambient temperature reporting. Each DAE can contain a mixture of all
drive types (Flash, SAS, and NL SAS).
The Disk Array Enclosures (DAE) are highly available, high performance, storage-system
components that communicate with the disk drives via a 6 Gb Serial Attached SCSI (SAS)
interconnect interface. A DAE connects to another DAE or an SPE and is managed by the
storage system software.
Note that both the 15- and 25-drive DPEs can be used with the 4U 60-drive DAE. However, 25-
drive DAEs are not supported.
The rear view of a 15 DAE contain two LCC cards and two redundant power supply/cooling
modules. Both the LCC’s and PSU’s are specific for the 3U, 15” disk drive DAE. Power
Supply/Cooling Module A and LCC A are located on the bottom and Power Supply/Cooling
Module B and LCC B are located on the top.
The LCCs and Power Supplies are locked into place using captive screws to ensure proper
connection to the midplane. All DAE FRUs are hot swappable but precautions must be taken to
ensure non disruptive operation. If a Power Supply is removed from the enclosure, the
enclosure will shutdown after two minutes. Be sure to download and run the Procedure
Generator before removing or installing any components.
Shown in this slide is the rear view of a VNX5100 15-drive DAE.
On each of the LCCs, an LCC Enclosure ID is provided. This is a seven-segment LED decimal
number display. The LCC Enclosure ID appears on both LCCs (A and B) within an enclosure and
should always display the same Enclosure ID. The Enclosure ID is set during system boot. The
LCCs also have Power and Fault LEDs.
Each LCC includes a Bus (Loop) ID as well. This indicator includes two seven-segment LED
decimal number displays. The SP initializes the Bus ID when the operating system is loaded. The
LCC in a DAE connects to the Storage Processor and the other DAEs with twin-axial copper
cables in a daisy-chain (loop) topology. The LCC cable from the previous DAE LCC A or Storage
Processor A back-end SAS port is plugged into the LCC A input which is marked with double
circles. The LCC cable going to the next DAE LCC A in the same loop is plugged into the LCC A
output marked with double diamonds. The same is true for the LCC B input and output. All
back-end bus cables are keyed to prevent incorrect cabling.
Note that the DAE SPS Monitor jacks are not used by the VNX platform.
Shown here is a graphical representation of the SAS cabling in an SPE based VNX storage
system. The Storage Processors connect to the DAEs with twin-axial copper cables. The cables
connect LCCs in a storage system together in a daisy-chain or loop topology. The first DAE
connected to the Storage Processor output SAS Port will be designated Enclosure 0. Each DAE
connected after the first DAE will increment the enclosure number by one. All enclosures
connected to SAS Port 0 will display a Loop ID of 0.
Each LCC independently monitors the environmental status of the entire enclosure, using a FRU
monitor program. The monitor communicates status to the Storage Processor, which polls disk
enclosure status. Internally, each DAE LCC connects to drives in its enclosure in a point-to-point
fashion through a switch. For traffic from the system’s Storage Processors, the LCC switch
passes the input signal from the input port to the drive being accessed; the switch then
forwards the drive’s output signal to the output port, where cables connect it to the next DAE
in the loop. If the target drive is not in the LCC’s enclosure, the switch passes the input signal
directly to the output port. At the unconnected output port of the last LCC, the output signal
from the storage processor is looped back to the storage processor. LCC firmware also controls
the LCC port-bypass circuits and the disk-module status LEDs. You can add or replace an LCC
while the disk enclosure is powered up. A 6 Gb SAS I/O Module replacement requires an SP
shutdown.
Cabling between the DPE and optional DAEs uses SAS cables. The connectors on SAS cables
have icons indicating each end.
The VNX 5500, 5300, and 5100 SAS ports on the DPE are labeled 0 and 1. Port 0 is connected
internally to the SAS expander that connects all the internal DPE disks. Since Port 0 is already
connected internally to the DPE disks, the first DAE is connected to Port 1 to balance the load
on the SAS ports. The second DAE is connected to Port 0; the third DAE is connected to SAS1,
and so forth
Cabling between the SPE and DAEs uses SAS cables. The connectors on SAS cable connectors
have icons indicating each end.
For the VNX 7500 and VNX 5700 model the I/O module in slot 0 of each SP has SAS ports
labeled 0 and 1.
• SP A slot 0 Port 0 is connected to the SAS expander on DAE 0 LCC A.
• SP A slot 0 Port 1 is connected to the SAS expander on DAE 1 LCC A.
• SP B slot 0 Port 0 is connected to the SAS expander on DAE 0 LCC B.
• SP B slot 0 Port 1 is connected to the SAS expander on DAE 1 LCC B.
Probably a whole lot of meaningless info not really needed but hey, why not. Apologies if this stuff has already been shared.
VNX2 series documentation:
For the official record file systems on VNX can blow me. Ask me about Isilon.

