One of the companies I worked for got a Netapp filer and I loved the fact that it would dedupe the data that was sitting on disk. I got over 40% more storage just by having that sweet little feature on. I was thinking, “How awesome would it be to dedupe my memory?” Getting more memory out of my servers would be a nice thing. Well as it turns out, VMware does this already, but they call it “Transparent Page Sharing.” ...
Jumbo frames can be useful to optimize IP networks, especially in storage networking. This post should help to explain why using jumbo frames can be useful. I’m not Jumbo, I’m just big boned! First, let’s define what we mean by the term jumbo frame. As you can imagine it’s bigger than a normal frame. A Jumbo frame simply means any frame with an MTU larger than 1500 bytes. What exactly does that mean? To really understand that we need to look at an Ethernet frame. The diagram below shows a hastily thrown together Ethernet frame and most of the frame we’re not concerned with for this topic. Parts of the frame are used for determining where the frame is headed, where it came from and to make sure it arrived intact. The section we’re looking at is the “Data” or “Payload” section of the frame. ...
Sometimes we need a quick set of statistics to see what is going on inside a vSphere host. Sort of like using Microsoft’s task manager on a Windows server, we can quickly take a look at what some performance stats on the VMware hosts. A couple of the tools to do this are the esxtop and resxtop commands. Esxtop and resxtop are basically the same with the exception that esxtop must be run directly on the vSphere host by connecting via SSH. Resxtop can be run remotely from the vMA perhaps. Below is a screenshot of the two tools running side by side. Aside from the refresh rates not being matched up, you can see that they are both showing the same information. ...