Jperf is a Java-based graphical interface for iperf, the network performance tool we rely on for validating network throughput on Isilon installations.

On OS X, installing jperf can require multiple steps:

jperf Executable for OS X can be downloaded from:


Once you’ve downloaded it and copied the software to your /Applications/Utilities folder you will receive this message if you’re on OS X Mavericks or above:

"To open “jperf” you need to install the legacy Java SE 6 runtime."

Download from:


Java for OS X 2014-001


Java for OS X 2014-001 includes installation improvements, and supersedes all previous versions of Java for OS X. This package installs the same version of Java 6 included in Java for OS X 2013-005.

Please quit any Java applications before installing this update.

See for more details about this update.

See for information about the security content of this update.


Once you have:


You will receive a message saying:

“jperf” can’t be opened because it is from an unidentified developer.

Instead, option-click (⌥ option key) and you will receive this message.

“jperf” is from an unidentified developer. Are you sure you want to open it?

Opening “jperf” will always allow it to run on this Mac.

You may then receive an error message that requests that you place iPerf in your PATH. Open a terminal window and execute the following:

export PATH=$PATH:/"path to perf"/iperf-2.0.5-i686-apple-darwin10.5.0/iperf

If the error persists, launch the executable directly within the app via terminal by issuing:

open /“Path to”/