How to Resolve “Cabling is inconsistent between SPs” on EMC VNX
EMC VNX family is one of most popular storage families over the world for virtualization or other purposes. EMC has provide two tools for managing VNX Storage Array:
EMC Navisphere Command Line Interpreter
- EMC Unisphere (Web Based GUI)
The management tools are using for initializing the storage array, create pools, create RAID groups and any other management tasks. Also the management tools will inform you about any fault on storage system.
“Cabling is inconsistent between SPs” is a fault on storage system and it’s related to SAS cables between DPE and DAEs.
Why the fault is happened?
Let’s review the cabling between DPE and DAEs in VNX storage system.
As an example, VNX5200 has two storage processor (Same as most VNX storage arrays) and each SP has two mini-HD SAS connection ports. You need to use mini-SAS HD to mini-SAS cable for connecting SP SAS ports to additional disk array enclosures. You need to four cables and you can add first of two DAEs by the cables to DPE.
There is two type of cables:
- mini-SAS HD: This is the cable for connecting DPE to LCC (Link Control Cards) ports.
- mini-SAS: This type will use for expanding storage array and connecting DAE LCC ports to additional DAE LCC ports.
The below figure shows standard cabling for adding two additional DAE to a EMC VNX5200 DPE:
Top DAE, that’s a 2U 25 disks DAE and bottom َِDAE is a 3U 15 disks DAE. Additional DAEs, up to the system maximum, can be added by extending the loop, connecting cables from LCC A and B of a DAE (Two Diamond Symbols) to the appropriate LCC ports (Two Circles Symbol) of an additional DAE. Cables from DAE to DAE on these loops are mini-SAS to mini-SAS cables. Each BE loop can support up to 10 DAEs. For more details on additional DAE cabling, see your VNX hardware information guide.
Now, answer to the question. Why we will face with “Cabling is inconsistent between SPs” ?
If you didn’t do cabling according to storage array installation guide or the above standard sample, maybe you did connect both bus to a DAE accidentally. Check all SAS cables and reconnect them correctly.