Yellow Bricks

by Duncan Epping

ESX

Podcast 79 – Building your homelab

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The VMTN/PlanetV12n Podcast 79 was all about homelabs. You can download the MP3 here, subscribe to the podcast via iTunes here, or listen in live here every wednesday. As always I tried to capture most links that have been posted. The link by the way also contains a summary of what has been discussed. Have fun:

NIC Teaming load balancing does not work with global vSwitch configuration on ESX 3.5

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A week ago a colleague contacted me about the fact that he had issues with load balancing on “Virtual Port ID”. Only a single NIC was utilized while running over 10 VMs on a single host. When changing the order of the NICs the traffic would flip over but again no load balancing. I remembered a KB article from months ago and pointed him to the article. Yesterday on the VMTN Community someone reported a similar issue with his ESX 3.5 environment. I referred to the article again and it solved the problem. Might be worth checking your setup in terms of load balancing. Is your second NIC actually being used? And if not here’s a short description of the problem and the solution:

Source

  • Symptom: NIC Teaming load balancing properties do not take effect with global vSwitch configuration settings.
  • Resolution: Override the load balancing order at the port group level, under Policy Exceptions, select the checkbox and choose the proper load balancing from the dropdown menu. Please note that this workaround only works until the next reboot of ESX.

My Homelab

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This weeks VMTN podcast is about Homelabs. John  Troyer asked on twitter who had a homelab and if they already posted an article about it. Most bloggers already did but I never got to it. Weird thing is that the common theme for most virtualization bloggers seems to be physical! Take a look at what some of these guys have in their home lab and try to imagine the associated cost in terms of cooling, power but also the noise associated with it.

I decided to take a completely different route. Why buy three or four servers when you can run all your ESX hosts virtually on a single desktop. Okay, I must admit, it is a desktop on steroids but it does save me a lot of (rack)space, noise, heat and of course electricity. Here are the core components of which my Desktop consists:

I also have two NAS devices on which I have multiple iSCSI LUNs and NFS shares. I even have replication going on between the two devices! Works like a charm.

There’s one crucial part missing. On my laptop I use VMware Player but on my desktop I like to use VMware Workstation. Although VMware Player might just work fine, I like to have a bit more functionality at my disposal like teaming for instance.

That’s my lab. I installed 3 x ESXi 4.0 Update 1 in a VM and installed Windows 2008 in a VM with vCenter 4.0 Update 1. Attached the ESX hosts to the iSCSI LUNs and NFS Shares and off we go. Single box lab!

Real life RAID penalty example added to the IOps article

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I just added a real life RAID penalty example to the IOps article. I know Sys Admins are lazy,  so here’s the info I just added:

I have two IX4-200Ds at home which are capable of doing RAID-0, RAID-10 and RAID-5. As I was rebuilding my homelab I thought I would try to see what changing RAID levels would do on these homelab / s(m)b devices. Keep in mind this is by no means an extensive test. I used IOmeter with 100% Write(Sequential) and 100% Read(Sequential). Read was consistent at 111MB for every single RAID level. However for Write I/O this was clearly different, as expected. I did all tests 4 times to get an average and used a block size of 64KB as Gabes testing showed this was the optimal setting for the IX4.

In other words, we are seeing what we were expecting to see. As you can see RAID-0 had an average throughput of 44MB/s, RAID-10 still managed to reach 39MB/s but RAID-5 dropped to 31MB/s which is roughly 21% less than RAID-10.

I hope I can do the “same” tests on one of the arrays or preferably both (EMC NS20 or NetApp FAS2050) we have in our lab in Frimley!