How do I improve network performance between VM’s

Let’s create an example situation.  You have two machines a application server and a database.  These machines do a lot of network traffic to each other.  You want to ensure they have the best possible performance.  In vmware worlds there are a few tricks to help you out.  First make sure your using the latest vmknic available.  After you have upgraded the nic’s the only thing left is to take advantage of the vmware ring buffer.

What is the vmware ring buffer?

Since virtual switches are defined as software dumb switches they operate in ram.  Ram is really fast.  So if you can send a message without leaving your virtual switch it can be really fast.   The ring buffer exists on each esxi host and where possible allows guests to communicate with each other (layer 2 so they have to be in the same subnet)  without involving anything but RAM.  You can see a 2X performance gain by just using the ring buffer.

How do I use it?

Keep your talking vm’s on the same host using affinity rules and your all set.

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