High packet drop over FCoE setup

[aymen.mohammed]

We have nexus 5k switch connected to storage array through FCoE 10GB interface and with blade chasse support FCoE. We are facing a hug latency on the traffic flow between the server and the storage. Can some one help me to solve this issue? Also do we need to setup the jumbo frame and modify the MTU size?

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[Robert Burns]

Aymen,

MTU should not be an issue.  No need to modify the MTU for regular ethernet traffic, unless you're using IP storage such as iSCSI. 

Let's narrow down the problem first. 

1. Do you see packet loss/performance issues on other servers connected to the same N5K(s)?

2. Are you seeing any packet drops on the N5K interfaces or GATOs ASIC? 

show interface e1/20 counters errors

show interface e1/20 flowcontrol

show interface e1/20 priority-flow-control

show system internal ethpm errors | egrep Ethernet1/20

show hardware internal gatos port ethernet 1/20| egrep -i err

I would check these counters on both the host facing and arrary facing interfaces.

3. What is the exact array that is FCoE attached?

4. Do you have a topology diagram?

5. What are the server side adapters, firmware and driver versions being used (include the OS on the host).

Regads,

Robert