Design connection between MDS and Storage

[BertiniB]

Hello
Regarding connecting the storage to the MDS, usually the Storage has two Storage Processors (or controllers) A and B. Do I connect them crossed between the SP and the MDS (like vPC) or Controller A goes only to MDS Fabric A and Controller B goes only to Fabric B? I have seen the two types on the internet, but what should be my go to?

Which one is the right one?

or

[jaton]

For connecting the storage controllers (SP A and SP B) to the MDS switches, the recommended and more common best practice is to connect each Storage Processor (controller) to both MDS fabrics, providing redundancy and load balancing. Here’s how it typically works:

- Controller A should connect to both Fabric A and Fabric B.
- Controller B should also connect to both Fabric A and Fabric B.

This setup is sometimes referred to as a cross-connect, where each storage controller has paths to both fabrics, ensuring that if one MDS switch or fabric fails, the storage remains accessible. This configuration maximizes redundancy and allows for high availability, as it avoids any single point of failure.

In your options:
- The image BertiniB_0-1731353710724 seems to be the right one if it reflects this cross-connection approach, where each storage processor is connected to both MDS switches.

By contrast, a setup where Controller A connects only to Fabric A and Controller B only to Fabric B would not offer the same level of resilience. If one fabric fails, half of your storage paths would be lost, potentially affecting performance and availability.

[BertiniB]

Thanks for the reply @jaton !
But if I lose the fabric A, doesn't the HBA on the Fabric B still have access to the LUNs via SP B? Both Storage Processors answer for all the LUNs, don't they?