Windows Azure Pack (WAP) simplified: Prepping OS Image Disks for Gallery Items

To publish a gallery item in Windows Azure Pack (WAP), the associated OS image disks, i.e. vhd files, must be set according to what’s in the readme file of a gallery resource package. For those who are not familiar with the operations, this can be a frustrating learning experience before finally getting it right. This blog post is to address this concern by presenting a routine with a sample PowerShell script [download] to facilitate the process.

Required Values of OS Image Disks for WAP Gallery Items

For example, below is from the readme file of the gallery resource package, Windows Server 2012 R2 VM Role. It lists out specific property values for WAP to recognize a vhd as an applicable OS image disk for the Role. To find out more about WAP gallery resources, the information is available at http://aka.ms/WAPGalleryResource.

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As a gallery item introduced into vmm and WAP, the item then becomes available when a tenant is provisioning a Role as shown below.

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There are several steps involved including:

  • Prepping vhds of and importing resource extension of the gallery item, as applicable, to vmm server library shares
  • Importing resource definition to WAP

Here, prepping vhds is the focus. And the process and operations are rather mechanical as detailed in the following.

Process and Operations

The script below illustrates a routine for a vmm administrator to set required property values on applicable OS image disks in a target vmm server’s library shares, . This sample script is available for download.

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Line 23 connects to a target vmm server.

Line 25 builds a list of vhd objects the prefix, ws2012r2, in their names. Which suggests a vmm administrator to develop a meaningful naming scheme for referenced resources.

Line 27 and 28 display settings of the vhd files before making changes.

Line 30 to line 35 are to set the values to specific fields including OS, familyname and release according to the readme file of a particular gallery resource package, for example, WS2012_R2_WG_VMRole_Pkg. And as preferred, one can also default a product key to a vhd.

The foreach loop goes through each vhd in the list and set the values. WAP references the tag values of a vhd file to realize if a vhd is applicable for various workloads. Make sure to add all tag values specified in the readme file, as demonstrated between line 41 and line 44 to build the list. Line 46 to line 52 sets all specified values to corresponding property fields of a currently referenced vhd file.

Finally upon finishing the foreach loop,  line 56 and line 57 present the updated settings of the processed vhd files for verification.

User Experience

Here’s an example of running the script:

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And with a vmm admin console of the target server, go to Library workspace and right-click an updated vhd disk to verify the property values are correctly set, as shown below.

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At this time, with correctly populated property values and tags, the vhds are ready for this particular WAP gallery item, Windows Server 2012 R2 VM Role.

For all the gallery items which WAP displays, a vmm administrator must reference the readme file of each gallery resource package and carry out the above exercise to set property values of the applicable OS image disks. Pay attention to the tags. Missing a tag may invalidate an image disk for some workload and inadvertently prevent that workload from being available for a tenant to provision an associated VM Role in WAP, despite the OS is properly installed on the disk.

Closing Thoughts

The tasks of prepping OS imaging disks for WAP gallery items are simple and predictable. Each step is however critical for successfully publishing an associated gallery item in WAP. Like many mechanics, understand the routine, practice, and practice more. A vmm administrator needs to perform these operations with confidence and precision. The alternative is needless frustration and delay, while both are absolutely avoidable at this juncture of deploying WAP.