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How to Query VM Disk Format in vSphere 5

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Prior to vSphere 5, it was not trivial to identify the particular disk format for a given virtual machine's disk. Using the vSphere Client, you would see a virtual machine's disk be displayed as either thin or thick. The problem with this is that the "thick" format can be either:

  • zeroedthick - A thick disk has all space allocated at creation time and the space is zeroed on demand as the space is used
  • eagerzeroedthick - An eager zeroed thick disk has all space allocated and wiped clean of any previous contents on the physical media at creation time. Such disks may take longer time during creation compared to other disk formats.

Users would not be able to distinguish the exact type using the vSphere Client or the vSphere 4 APIs. With the release of vSphere 4, VMware did introduce a new property in the vSphere 4 API called eagerlyScrub which was supposed to help identify whether a virtual disk was allocated as an eagerzeroedthick disk. Unfortunately there may have been a bug with the property as it never gets modified whether a disk is created as zeroedthick or eagerzeroedthick.

The only method that I was aware of to truly figuring out the disk format would be to manually parse the virtual machine's vmware.log file to identify the disk type which I wrote a script for in 2009.

During the vSphere 5 beta, I had noticed the vSphere Client UI now properly displays all three virtual machine disk format: zeroedthick (displayed as flat), thin and eagerzeroedthick (displayed as thick).

Seeing that VMware now displays the three different formats, I wanted to see if it was possible to extract this using the vSphere 5 APIs and not have to rely on the hack of reading the vmware.log files. It turns out that the eagerlyScrub property is now functioning properly when a VMDK is provisioned or has been inflated/converted to the eagerzeroedthick format. I wrote a simple vSphere SDK for Perl script called getVMDiskFormat.pl which allows you to extract the disk formats of all virtual machines connecting to either vCenter or directly to an ESX(i) host.

The script allows for two types of output: console (directly on the console) or csv (creates .csv file)

If you select csv output, by default it will be stored in a file called "vmDiskFormat.csv". You also have the option of specifying the filename by using the --filename flag and providing a name of your choosing.

You can then load the csv file into excel and easily sort through the various disk format types.

All this is already included in the latest version of the VMware vSphere Health Check Report 5.0 if you want a centralize report that includes virtual machine disk format.

How to Install VMware VSA in Nested ESXi 5 Host Using the GUI

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We upgraded the ghettoDatacenter to vSphere 5 this weekend and one of the things I wanted to play with was the new VMware VSA (vSphere Storage Appliance). Since we only have a single host, running nested ESXi would be our only option and this would allow us to easily deploy three vESXi 5.0 hosts and vCenter to tinker with the new VMware VSA.

UPDATE (09/16/12): You can use the same process outlined in this article to run the new VMware VSA 5.1 (vSphere Storage Appliance) in a nested ESXi configuration. Below is a screenshot of running VSA 5.1 in Nested ESXi 5.1.

One caveat in using vESXi hosts to test the VSA is during the selection of your ESXi hosts, VSA expects the hosts to be EVC capable. The VSA will create a vSphere Cluster and automatically enable EVC baseline based on your cpus. As you may or may not know, EVC can not be supported in a vESXi host and this would prevent you from selecting these hosts.

Luckily this issue was solved by a Vijay in his blog post here. There is a configuration file called dev.properties located in C:\Program Files\VMware\Infrastructure\tomcat\webapps\VSAManager\WEB-INF\classes which contains a line specifying whether or not EVC should be configured "evc.config". This configuration file appears to be used by VMware internally for some type of development but by changing the parameter from true to false, the VSA will support non-EVC capable hosts and not enable EVC for the VSA vSphere cluster.

Note: This is most likely not supported by VMware, please use at your own risk along with modifying any other values within this file.

Now, you might wonder if Vijay had already documented this process in his blog, why am I repeating it? Well the issue that Vijay had identified by tweaking this configuration file was that the VSA GUI installer did not detect the change and had to rely on an alternative method of installation using the commandline. Though not ideal, this method does work but for first time evaluators of the VMware VSA, the various commandline options can overwhelm or confuse users. It would be great if one could using the VSA GUI to perform the installation which is much more intuitive and that is reason for this article.

For the VSA to detect the new changes, you will need to restart the VMware VSA and then the vCenter Service under the Windows Services utility. I am not sure why both services need to be restarted, but I guess the VSA extension is not updated when just the VSA is restarted which is unfortunate. 

Once both services have started up, open a new vSphere Client session to your vCenter Server and proceed with the VSA installation. During the selection of the hosts, you will now have the option of selecting your vESXi 5 hosts and a warning message is presented stating "Unsupported Hardware" but the installer will allow you to continue on. 

After you have selected either two or three of your vESXi hosts, you will be prompted once more that this configuration is not supported nor in the VMware HCL, go ahead and click OK.

After this, you will be able to go through the rest of the VSA installation as long as meet the default requirements of the VMware VSA noted in the documentation.

So if you have some interests in the new VMware VSA and do not have physical hardware to test with, you should consider deploying a couple of vESXi hosts and kick the tires with the new VSA.

How to Run Windows 8 on vSphere 5

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There's been a lot of hype/talk about Windows 8 and if you wanted to test drive the new OS, you might consider using the latest release of VMware Fusion 4.0.1 or VMware Workstation 8 as Windows 8 is an officially supported guestOS. Though what if you wanted to run it in your vSphere 5 environment? Well you can with a small hack.

Even though it's not listed as a supported guestOS, you can manually tweak the .vmx configuration to get ESXi 5 host to recognize the guestOS type. You just need to create a generic Windows 2008 system and then from the commandline or by exporting the .vmx using the datastore browser and then edit the configuration file. You will need to make the following change to the guestOS paramater:

guestOS = "windows8srv-32"
guestOS = "windows8srv-64"

One you have made this change, you will need to re-register the virtual machine or reload the configuration using vim-cmd vmsvc/reload operation.

Another method just using the vSphere Client without any modifications to the .vmx is to just create a virtual machine and select any guestOS type. Once the virtual machine has been created, there is actually an option in the guestOS to select Windows 8 32 or 64bit that can be selected. If you wish to automate through the commandline, then you can use the method above or you can just use the vSphere Client.

Note: This is not officially supported from VMware of course, use at your own risk.

UPDATE1: It looks like when Windows 8 64bit is booting up for installation, the virtual machine core dumps with the following error:

vcpu-0| MONITOR PANIC: vcpu-0:NOT_IMPLEMENTED vmcore/vmm/intr/apic.c:1804

Something similar occurs with Windows 8 32bit that gets past the panic but an error message is thrown on the screen regarding HAL initialization failure. Currently there are no workarounds and I've reached out to some of the folks at VMware to see if there's any tweaks that can be made to support this. As I mentioned earlier, this is an unsupported OS/hack, so it may not work at all. Sorry to get everyone's hope up, the new Fusion 4.01 and Workstation 8 might still be your best bet to test out the new Windows 8.

UPDATE2: VMware has released a KB article http://kb.vmware.com/kb/2006859 regarding Windows 8 and vSphere 5 support. You can subscribe to the KB article for the latest update on running Windows 8 on ESXi 5.

UPDATE3:  I recently saw a tweet by Raphael Schitz and it looks like you actually CAN run Windows 8 on ESXi 5. Raphael was able to run Windows 8 by first running Xenserver as a virtual machine and then creating a Windows 8 VM that would run as a nested guestOS within Xenserver virtual machine (pESXi 5 -> Xenserver VM -> Windows 8 VM).

Note: You may need to reboot the system one additional time if it does not automatically load.

Here is a screen shot of Windows 8 64bit running on the latest release of Xenserver 6 running on ESXi 5: