SAN Connectivity to UCS infrastructure

[j.siddiqui]

Hello,

I need to know what is the best practice while connecting Dell Compellent SC8000 with CISCO UCS chassis. below is the scenerio.

Equipment:

1) 1x Cisco UCS blade chassis 

2) 2x FEX IOM with 8 ports

3) 2x Fabric Interconnect switches

4) 2x Cisco Nexus 5548UP switches

5) Dell Compellent SC8000 SAN (4x FC Ports and 4x 10G ports per controller)

There are two questions regarding connectivity:

1: where should I connect the SAN in the infrastructure either on Fabric Interconnects or on Cisco NEXUS 5548UP?

2: whether or not i can utilize all 8G FC and 10G FCoE ports together to get the max. bandwidth?

Thanks

[Walter Dey]

The basic question: what do you intend to use as a storage protocol: native FC, iSCSI or FCoE.

Although of course possible, I would not mix this 3 possibilities, and use only 1.

1) If you have already a N5k, I would recommend to attach your storage to it and not directly to UCS FI.

2) Bandwidth is in most cases not the limiting factor, but more IOPS; therefore just stick with eg. FC and create a port channel if necessary.

[j.siddiqui]

Hi Walter,

Thanks for your response, can you please let me know how can I utilize all the FC and FCoE ports of SAN, because opting for only one protocal will left half of the ports unused.

Also what is the benefit of attaching SAN to Nexus 5500 that Direct attach.?

[Walter Dey · Accepted solution]

Nexus5k supports all 3 protocols; you have to define a range (for the fixed ports as well the additional module ports) for Ethernet (used for IP storage = iSCSI/NFS) and native FC; the Ethernet ports can be used of course for native IP traffic.

Direct attachment is usually used in small and test environments (PoC), which might therefore avoid to invest e.g. in FC switches. If you go for direct attachment of native FC, your Fabric Interconnect have to be changed to FC switch mode, which has some limitations.

If your storage is used by other devices, go for N5k connectivity.