Thursday, September 16, 2010

ESXi 4.0.0 vs 4.1 Speed - 4.1 Not as fast

I've just upgraded my 4.0.0 ESXi box to 4.1.

...Well, lets not call it upgrading, the process I used was to pull my existing boot drive, install a new 8 gig  USB stick inside my Dell T710, and install a fresh copy of the Dell Installable 4.1 ESXi. This results in a fresh copy, and all I have to do is reattach my storage, import my .VMX files, and I'm back in business.

I once had a bit of a mess with the upgrade process from 3.0 to 3.5, so I settled on this method as being he safest. I even pull my drives when I do the upgrade, so there is no chance the installer will become confused and format my main datastore. Am I paranoid? It's happened before, and you only have to burn me once..

The process isn't that much more time consuming than an in-place upgrade. When your ESXi files are all on one drive/flash stick, and your datastores are all on another, you've got plenty of flexibility. I was able to do it within 30 minutes, because I really don't edit my ESXi configuration that much from default.

 I'm very interested in 4.1 because it has some neat power management interfaces. Look here, I can now track my wattage being burned on this server:

This is for a Dell T710 with 24 gig DDR3 memory, 2 Xeon 5660's,  4 600Gig SAS drives, and 4 1TB nSAS drives. I've yet to check how accurate this is with a KilloWatt or similar meter, but this sounds about right.

I'm also interested in memory compression - When you building redundancy by having two ESX servers, you need to have very similar configurations for processor / memory on your backup server, or you take a large performance hit. That's not always easy to budget for. If I can get away with my Exchange servers still running for a couple of hours on a server that is only 1/2 or 1/4 the memory of my main ESX, then I'll be happy. It's got to be quicker to compress memory than to swap it to disk - We'll see. I'll be testing that later on.

Service Console is now no longer an unsupported hack.

But really, the bit that gets me very interested the most is that vmware is now putting it's full weight behind ESXi - There won't be any more ESX! And to make this transition easier, you can now access vMotion from an ESXi 4.1 server. You still need licenses, but now it's nearly $10k cheaper to access this technology.

With my Ghetto-SAN comming online any week now, I'm very excited about this development.

BUT - There seems to be a but of a trade-off for the new things that 4.1 brings - It's just a tad slower than 4.0.0.

Once again, I do quick and dirty benchmarks to get a feel for things - Performance Test 6.1 isn't the best tool, but it's quick and makes for nice easy graphs to compare. After pouring through reams of iozone stats in Excel, I sometimes like quick, easy, and pretty.

My process was simple: Take a Performance Meter tests from a running 2008 R2 server before the upgrade to 4.1, and one after (with the new vmware tools loaded).

While 4.1 had better graphic performance (who cares!), it was around 2% slower for memory and CPU performance.

That's a small price to pay for new features, and I'm hoping it's just a result of new technology being focused on stability first, performance second.

Anyone else run benchmarks that can confirm or deny this?


  1. Thanks for the sharing the information! I will try out 4.0 today because I cannot admit that hyperV is faster than ESXI 4.1 (believe me it is!) Shame on you vmware.

  2. Well, if we're talking just a few VMs, then I'd say HyperV can give you a good run for the money.

    However, if you're running 30+ VM's like I am across multiple machines, then Microsoft can't touch vmware.

    So we're looking at a bit of a scalibility issue - Hyperv is fine for a small implementation, but VM for bigger ones.

    ... and Xen Desktop for Virtual Desktops.. they kill with their improved Citrix client for speed. Check Youtube for comparisons.