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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.

VMware officially releases vibddi for vSphere 4.1

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There were several product releases last week that got a lot of buzz on the inter-tube:

However, VMware actually released an additional product last week which snuck under the radar, vibddi.

I actually wrote about this unsupported and undocumented utility last year: How to inject custom drivers into an ESXi 4.1 image using vibddi? vibddi (pronounced vib d-d-i) stands for VIB (vSphere Installation Bundle) Disk Dump Image and it is a utility to help users easily customize ESXi images with custom drivers. This utility first appeared in the vSphere Auto Deploy appliance and it looks like VMware has finally released it as an official tool to support vSphere 4.1 image customization. You also may have heard about the new Image Builder tool with the release of vSphere 5, the origins of that utility actually came from vibddi.

If you are still using vSphere 4.1 and need to inject or modify drivers, I would highly recommend you take a look at the tool as it is extremely simple to use. For more details, please check out the new VMware KB article 2003316 documenting the details of the utility or my blog post. If you are using vSphere 5, you will need to use Image Builder as vSphere 4.1 is not supported and vice-a-versa with ESXi 5 with vibddi.

Note: There are some changes in the latest vibddi utility compared to the one found in the vSphere Auto Deploy such as injecting custom kickstart configuration file or license file. If you rely on these features, you may want to use the older version or manually update these after the system build.