PVS vDisk Auto Updates
We all know and love Citrix Provisioning Services (PVS) vDisk versioning in PVS 7.x and how this has enriched PVS administrators lives by significantly reducing the administration overhead involved with updates, but did you know you can further streamline the image release process by automating the boot of a PVS maintenance VM and integrating into SCCM/WSUS?
With the aforementioned combination, you can effectively schedule a vDisk update, ideal for use after Microsoft’s patch Tuesday. In this scenario, a specified PVS maintenance VM boots with a (delta) maintenance version of the vDisk image, then polls either SCCM, WSUS, or uses a customised script. Updates or new application installations are then installed and committed to the maintenance vDisk image, which is then promoted automatically to Test (you can control if this is promoted to Test, Production or left in Maintenance).
As the vDisk is in Test, we can immediately start the UAT test process with a defined set of UAT testers assigned to a set of Test PVS VMs, all done completely seamlessly. The only action an administrator is required to perform is accepting the UAT test results before promoting the image to Production, at which time any Production VMs will utilise the new image version upon system reboot (either coinciding with the next scheduled system reboot, or initiated by the admin).
It is also important to note that if a UAT test image does not exist, your UAT Test users will automatically fall back to the Production vDisk image, so they will not be left without their applications/desktops. This can be further streamlined by skipping the vDisk Boot Menu as the default option – great for those environments where you don’t have access to the VM console to select the boot option.
The following diagram illustrates one such process for Auto Updates with PVS vDisk Versioning:
This level of automation has several key benefits to the business:
- Further Reduction in Admin Overhead due to Prevention of Image Sprawl. Depending on your application delivery strategy, the number of vDisk images that are required within an organisation will vary. In many cases where application streaming technology or Citrix AppDisks has not been implemented, we see an increase to the number of vDisk images. So if you have eight vDisk images, you will need to manually apply eight lots of Windows updates. By leveraging vDisk Auto Updates, this step is essentially removed.
- Streamline UAT Process. By defining a set group(s) of UAT users, we can ensure that any image updates are adequately tested prior to full Production rollout. Typically, we wouldn’t even publish Production XenApp applications to these users (keep in mind that if no Test version exists, the image will default back to the Production vDisk version). This ensures that your UAT test users are always using the Test version when available, and have access to Production when not.
- Rapidly Test and Deploy Security Updates. As outlined in the above scenario, this process can expedite the Microsoft patching cycle by rapidly deploying and testing patches as soon as they are available. This ensures potential security vulnerabilities are addressed in a timely fashion.
- Stability. As we have defined a group of test users within the process, we can be sure that any issues are identified prior to Production rollout. Issues identified by the service desk can be tracked under a specific priority UAT queue for remediation.
You’ve probably noticed by now that this whole process is not just about the technology piece, but revolves a lot around internal processes as well. By creating a solid, repeatable vDisk update process, we can effectively identify any potential issues and remediate these before they reach Production. The use of PVS Automatic vDisk updates assists by expediting the whole process.
In order to configure PVS for automatic vDisk updates, please refer to the following Citrix articles:
- Configure PVS vDisk Update Management Using SCCM
- Create a Designated Update Virtual Machine and Add a Host Connection to Hosts Node
- Add a Managed vDisk to the vDisks Node Under vDisk Update Management
- Create an Update Task to be Performed at a Scheduled Time in Provisioning Services
GlassHouse Technologies has a proven track record of implementing both the business processes and technology to streamline image release cycles not only for PVS, but MCS (Citrix Machine Creation Services) and traditional deployment methods such as SCCM. Please reach out and let us know how we can help today.