How to maximize network utilization
Posted on 2010-09-02
My network topology is like this:
Dual Cisco 4507 Core Switches
Cisco 3750-E Server Switches & Access Switches Ports at 1Gbps
10Gbps backbone between Access/Core/Server Switches
My main storage server is a HP DL360 G4p connected at 1Gbps to the Server Switches
It connects to an EMC AX4 via an iSCSI connection at 1Gbps
The other day we had someone copying data from an SD card directly to the storage server over the network. So, removable storage dragged to share drive.
When the person was copying the data from the SD card (about 6 GB I think) it took up 36Mbps on our MRTG graphs and essentially shut everyone else out. Nobody could get to files or do anything. It was really bad. I told her to stop the copy and everything returned to normal. I assumed that it was the slow read rate of the SD card that caused the problem.
My question is this: Why, with a 1Gbps network and a 10Gbps backbone did that take down my network? I mean, all the other servers stopped the ability to talk, for the most part.
Second, I’m having similar issues today when the utilization on the network is reaching about 36Mbps to the APP server and things are dying. What can I do to help this? Why does it barely fill the capacity of the server and it kills everything?
I have verified that the connections are in fact 1000/full duplex connections.
Would a more powerful server help? Is my network not optimized somehow?