Scott's Weblog The weblog of an IT pro specializing in networking, virtualization, and cloud computing

NetApp ONTAP Simulator and ESX Server

In preparation for some NetApp training that I’ll be attending next month, I downloaded the NetApp ONTAP Simulator. The ONTAP Simulator runs on top of Linux (a few different distributions are supported) and allows you to simulate a NetApp Filer. This is pretty cool for a couple of reasons, not the least of which is that it allows you to perform testing of NAS and iSCSI operations without having an actual Filer. Unfortunately, I had some problems getting the ONTAP Simulator working in a virtual machine on VMware ESX Server.

To setup the ONTAP Simulator, I created a Linux virtual machine on ESX Server 2.5.3 and installed Red Hat Linux 9.0. Red Hat 9.0 is a supported distribution for the ONTAP Simulator as well as a fully supported guest OS on ESX Server, and so I didn’t expect any issues. However, after installing and configuring the simulator, I couldn’t get any network connectivity whatsoever. I had full connectivity to the guest OS, but not to the simulator.

Finally, after digging around in the documentation for the simulator, I came across a statement indicating that the network interface that was being used by the simulator had to be in promiscuous mode. That rang a bell: ESX Server, by default, doesn’t allow NICs in guest operating systems to be in promiscuous mode.

The fix is this:

echo PromiscuousAllowed yes > /proc/vmware/net/vmnic0/config

Replace vmnic0 in this command with whatever virtual switch or NIC team the virtual machine in question is using. Once I did this (from the Service Console on the ESX Server) and rebooted the virtual machine running the ONTAP Simulator, it worked like a champ.

(Note: You must be a current NetApp customer or partner in order to use the ONTAP Simulator.)

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