05-24-2012 08:52 AM
I have 2 VDX6720 with 4 ISLs. I´m doing a simple test. I copy a file between two hosts connected to the same switch, then I copy same file to another host connnected to the other switch and speed is better. Is this normal? I suppose than traffic through ISLs should be slower than local switch. Am I wrong?
11-12-2012 09:05 AM
There are many factors that affect copy speed, not just the network links. For example, the host itself has multiple layers of memory caching. The 2nd copy likley took advantage of the cached file contents and was quicker.
01-23-2013 12:31 PM
I would suggest running a test using the tool called IPERF. This is an open source tool that runs on two system. One system is configured as a listener for inbound connections (server) and the other system is configured as the traffic initiator (client). You can tweak the settings of IPERF to simulate different TCP window sizes and other parameters.
This is a good site to quickly see how to use the software.