Hi, I have been in a debait with another engineer on how we should connect our SAN fabric to our servers and CX4 series SAN array, via dual Cisco Fabric switches. i am looking for some input , to ether validate my argument or see if he is correct :-

we have currently :-

• All SP-A connections going to First switch which is Fabric A
• All SP-B connections going to second switch which is Fabric B
• Servers are Dual HBA cards. one connection from Fabric A and one from Fabric B

So if one switch Fails, the servers loose connectivity to the SP-B controller, and all the disks trespass.

he keeps mentioning that EMC says your not supposed to mix SPA and SPB connections in one fabric.

and that when disks trepass thats a normall function and quiet exceptable for reduncancy.

Ok yes this does work.

My understanding is that you can mix Both SP-A and SP-B connection on one Fabric.

So each HBA connection on the server can see paths to both SP-A and SP-B

• So SP-A1 connects to First Switch Fabric A
• SP-A2 connects to Second Switch Fabric B
• SP-B1 connects to First Swithc Fabric A
• SP-B2 connects to Second Switch Fabric B

and so on.

Hence if a switch fails, the server can still see connections to both A and B controllers.

Plus, if some servers only have a single HBA they can still see both controllers.

Thoughts please !!