EMC VNX5300 - Cabling with Two DAEs in VNX5300 File;Unified Platform

EMC® VNX5300™ Hardware Information Guide
82
EMC® VNX5300™ Hardware Information Guide
Cabling with two
DAEs in a VNX5300
File/Unified platform
Shown in the upcoming figures (Figure 74 on page 83 and Figure 75 on page 85) are
graphical representations of SAS cabling in a DPE-based VNX storage platform, the
VNX5300 File. The Storage Processors connect to the DAEs with SAS cables. The
cables connect LCCs in the DAEs of a storage platform together in a daisy-chain
topology.
The DPE is automatically Enclosure 0 (EA0). The DAE connected to SAS output
port 0 is Enclosure 1 (EA1).
The first DAE connected to the Storage Processor SAS output port 1 is designated
Enclosure 0 (EA0). Each DAE connected after the first DAE increments the enclosure
number by one. All enclosures connected to SAS Port 0 will display a ID of 0.
Figure 74 on page 83 shows the first example of a VNX5300 File platform with two
DAEs (one 3U, 15 disk drive DAE and the other a 2U, 25 disk drive DAE) or a
VNX5300 platform with a total of from 55 disk drives (if the DPE is a 3U, 15 disk
drive device) or 65 disk drives (if the DPE is a 3U, 25 disk drive device).
The SAS ports on the VNX5300 platform DPE are labeled 0 and 1. SAS 0 is connected
internally to the SAS expander that connects the internal DPE disks. Since SAS 0 is
already connected internally to the DPE disks, the first DAE is connected to SAS 1 to
balance the load on the SAS ports. The second DAE is connected to SAS 0, the third
DAE is connected to SAS 1, and so on.
In Figure 74 on page 83, notice that each DAE device supports two completely
redundant buses (LCC A and LCC B).
The rule of load or bus balancing is applied to all DAEs. That is, Bus 0 is Enclosure
Address 0 (EA0), Bus 1 is EA0, and so on. In the case of the VNX5300 platform, Bus 0
EA0 is the DPE (SP A and B). So, to balance the load, Bus 1 EA0 becomes the first
DAE (LCC A and B) in the cabinet with the next DAE (LCC A and LCC B) as Bus 0
EA1, and so on. If you have several DAEs in your VNX5300 platform, you can daisy
chain them within that particular bus. However, it is recommended that you balance
each bus. In other words, always optimize your environment by using every
available bus, and spreading the number of enclosures as evenly as possible across
the buses.
Note: On the DPE and DAE, each cable connector includes a symbol to denote the direction the
cable needs to connect to. The cable connector that has a double circle symbol is the input to the
device. The cable connector with the double diamond symbol is the output from the device.
IMPORTANT
!
Notice the description of the cable labels affixed to the SP to DAE cables.
The cables shown in Figure 75 on page 85 are:
Note: The cable colors shown in the example are orange for Bus 0 and blue for Bus 1.
◆ Cable 1, blue, DPE to 1
st
DAE (labels SP A SAS 1 to LCC A)
◆ Cable 2, blue, DPE to 1
st
DAE (labels SP B SAS 1 to LCC B)
◆ Cable 3, orange, DPE to 2
nd
DAE (labels SP A SAS 0 to LCC A)
◆ Cable 4, orange, DPE to 2
nd
DAE (labels SP B SAS 0 to LCC B)