Yellow Bricks

by Duncan Epping

5.0

Using the vCenter Appliance for the Web Client?

· ·

Today on twitter there was a discussion around having an appliance for the vSphere Web Client. I didn’t get the question as there’s already a vCenter Appliance out there. Apparently not everyone realised that the Web Client is part of the vCenter Appliance. On top of that you could even split out the components and use the vCenter Appliance just for Web Client functionality. I remembered seeing an article from one of my colleagues not too long ago. I dug up the links and here they are. I included a short snippet so you know what to expect. These articles are by Michael Webster so all credits go to him:

Deploy vSphere Web Client without Additional Windows Server License

Prior to running through the steps below you should have downloaded and deployed the vCenter Server Virtual Appliance (VCVA) from the VMware web site. This process assumes you already have the VCVA connected to the network and configured with the correct timezone already. To de-register the local embedded vCenter System and to register an existing vCenter Server with the vSphere Web Client do the following….

This is the first step you can take to get the vSphere Web Client up and running. But what if you want to provide some additional redundancy. Or what if you have dozens of people literally using the Web Client and want to add some load balancing? Well Michael thought about that as well and came up with a cool solution for this.

Increase vSphere Web Client Availability and Scalability for Enterprise Environments

In the above design I’ve chosen to use the vCenter Virtual Appliance with the vCenter Services disabled to act as the vSphere Web Client Servers. I’ve used a F5 BIG-IP LTM VE to provide load balancing for the vSphere Web Client User access to the vSphere Web Client Servers, as well as for the vCenter Servers to access the vSphere License Plug-in. You can use any load balancer that will successfully load balance HTTPS traffic on port 9443, which is the port the vSphere Web Client uses.

I think this is a cool solution, and considering the Web Client is the way forward it is definitely an option exploring. I do want to point out that this has more than likely not been explicitly tested by VMware and I am uncertain if it is supported. I have reached out to our vCenter experts however to comment on it.

ESXi commandline work….

· ·

I am just playing around in my lab and needed to do a couple of common ESXi commandline tasks which I figured I would document as they will come in handy at some point.

  • List all VMs registered to this host (This reveals the Vmid needed for other commands)
    vim-cmd /vmsvc/getallvms
  • Unregister a VM
    vim-cmd /vmsvc/unregister <Vmid>
  • Register a VM
    vim-cmd /solo/register /path/to/file.vmx
  • Get power state of a VM
    vim-cmd /vmsvc/power.getstate <Vimid>
  • Power off a VM
    vim-cmd /vmsvc/power.off <Vmid>
  • Power on a VM
    vim-cmd /vmsvc/power.on <Vmid>

vShield App broke down on the host that is running vCenter now what?

· ·

I was playing around with vShield App and I locked out my vCenter VM which happened to be hosted on the cluster which was protected by vShield App. Yes I know that it is not recommended, but I have a limited amount of compute resources in my lab and I can’t spare a full server just for vCenter so I figured I would try it anyway and by breaking stuff I learn a lot more.

I wanted to know what happened when my vShield App virtual machine would fail. So I killed it and of course I couldn’t reach vCenter anymore. The reason for this being is the fact that a so-called dvfilter is used. The dvfilter basically captures the traffic, sends it to the vShield App VM which inspects it and then sends it to the VM (or not depending on the rules). As I killed my vShield App VM there was no way it would work. If I would have had my vCenter available I would just vMotion the VMs to another host and the problem would be solved, but it was my vCenter which was impacted by this issue. Before I started digging myself I did a quick google and I noticed this post by vTexan. He had locked himself out by creating strict rules, but my scenario was different. What were my options?

Well there are multiple options of course:

  1. Move the VM to an unprotected host
  2. Disarm the VM
  3. Uninstall vShield

As I did not have an unprotected host in my cluster and did not want to uninstall vShield I had only 1 option left. I figured it couldn’t be too difficult and it actually wasn’t:

  1. Connect your vSphere Client to the ESXi host which is running vCenter
  2. Power Off the vCenter VM
  3. Right click the vCenter VM and go to “Edit Settings”
  4. Go to the Options tab and click General under Advanced
  5. Click Configuration Parameters
  6. Look for the “ethernet0.filter0” entries and remove both values
  7. Click Ok, Ok and power on your vCenter VM

As soon as your vCenter VM is booted you should have access to vCenter again. Isn’t that cool? What would happen if your vShield App would return? Would this vCenter VM be left unprotected? No it wouldn’t, vShield App would actually notice it is not protected and add the correct filter details again so that the vCenter VM will be protected. If you want to speed this process up you could of course also vMotion the VM to a host which is protected. Now keep in mind that while you do the vMotion it will insert the filter again which could cause the vCenter VM to disconnect. In all my tests so far it would reconnect at some point, but that is no guarantee of course.

Tomorrow I am going to apply a security policy which will lock out my vCenter Server and try to recover from that… I’ll keep you posted.

** Disclaimer: This is for educational purposes, please don’t try this at home… **

Repeated characters when typing in your VMs remote console?

· ·

Today I was working on a couple of test scenarios in a remote lab. For some reason the latency was a lot higher than normal and I was very difficult to type anything in the Remote Console through the vCenter Client. Every single character I tried popped up 2 or 3 times… which makes it very difficult to type a password as you can imagine. I knew I read a KB article about this exact problem a long time ago. Considering it is KB 196 I probably wasn’t the first to bump in to this. The solution is fairly simple:

  • Power off the VM
  • Edit Settings
  • Click the Options Tab
  • Click “General”
  • Click “Configuration Parameters”
  • Click “Add Row”
  • Enter the name: keyboard.typematicMinDelay
  • Enter the value: 2000000

Although the KB article doesn’t mention it, this also applies to vSphere 5.0.

What happens to powered off VMs when a host fails?

· ·

I had the question today what happens to a powered off VM when the host they are registered against fails? This customer always has multiple powered off VMs and was afraid their VMs would show up as orphaned. I was pretty confident that the VM would be re-registered against one of the remaining hosts in the cluster, but I validated it just in case and this is what the events section of the VM shows:

Relocating from cs-tkmt-h08, emc-vnx-fcoe to cs-tkmt-h05, emc-vnx-fcoe

In other words, the VM is relocated from my ESXi host cs-tkmt-h08 to cs-tkmt-h05. No need to worry about orphaned VMs and manually registering them against the remaining hosts… vSphere does it for you.