3750-E with Equalogic SAN Latency Issues

[sketterman]

We are having issues with our Equalogic SAN reporting Disk Latency Issues. Equalogic points to the switches which show no signs so far of any latency issue or drops. These are 3750E series switches with no routing, just switching and all data is going through one single switch so no transfers across a network.

Any ideas would be really appreciated.

[jim_berlow]

We don't know enough about the situation to identify exactly what the issue is. Here are a couple things, though:

- Are speed / duplex's matched correctly?

- Are you oversubscribing the 3750E? This switch has a blocking switch fabric that could create issues. Look at the Cisco 4900 series for non-blocking models (better for high transaction, lossless environments like SANs)

- Are there switch bugs?

- Are there other devices connected to these switches? Are they on the same VLAN?

- What does the utilization look like on the ports where the SAN is connected?

There are lots of other potential issues as well. I hope this helps, though.