Product Documentation

Updating vDisks

Sep 28, 2016

It is often necessary to update an existing vDisk so that the image contains the most current software and patches. Each time the vDisk is to be updated, a new version of that vDisk is created (VHDX file) to capture the changes without changing the base vDisk image.

Updating a vDisk involves the following:
  • Create a new version of the vDisk, manually or automatically.
  • Boot the newly created version from a device (Maintenance device or Update device), make and save any changes to the vDisk, then shut-down the device.
  • Promote the new version to Production.

The following illustrates the general promotion of a vDisk update:

The availability of the updated version depends on the current promotion of that version (Maintenance, Test, or Production), and the type of device attempting to access it (Maintenance Device, Update Device, Test Device, or Production Device).

If updating a device that uses a personal vDisk image, ensure compatibility in your production environment using this procedure:

Note: Updating images for devices that use a personal vDisk, must be done on a virtual machine that does not have a personal vDisk attached. Otherwise, updates are saved to the personal vDisk image rather than the virtual machine image.
  1. Create a new maintenance version of the vDisk.
  2. Make any necessary updates to the maintenance version.
  3. Promote the new maintenance version to test.
  4. Boot the PvD test device, and then verify updates were made.
  5. Promote the test version to production.
Update Scenarios
The following vDisk update scenarios are supported:
  • Manual Update – An administrator may choose to update a vDisk manually by creating a new version of that vDisk, and then using a Maintenance device to capture updates to that version. Manual updates are initiated by selecting the New button on the vDisk Versions dialog. The Access column on the vDisk Versioning dialog displays that the newly created version is currently under maintenance. While under maintenance, this version can only be accessed and updated by a single Maintenance device. Multiple Maintenance devices can be assigned to a vDisk. However, only one device can boot and access that version of the vDisk at any given time. During that time that Maintenance device will have exclusive read/write access. For details, refer to Manually Updating a vDisk Image
  • Automated Update – Creating automated updates saves administration time and physical resources. Updates are initiated on-demand or from a schedule and are configured using vDisk Update Management. If updating automatically, the Access column on the vDisk Versioning dialog displays that the newly created version is currently under maintenance. While under maintenance, this version can only be accessed and updated by the one Update device to which it is assigned (only one Update Device exists per vDisk). For details, refer to Automating vDisk Updates.
    Note: vDisk Update Management is intended for use with Standard Image Mode vDisks only. Private Image Mode vDisks can be updated using normal software distribution tool procedures. Attempting to register a Private Image Mode vDisk for vDisk Update Management, or switching a vdisk that is already registered, will cause errors to occur.
  • Merge – Merging VHDX differencing disk files can save disk space and increase performance, depending on the merge option selected. A merge update is initiated manually by selecting the Merge button on the vDisk Versions dialog, or automatically when the maximum vDisk versions count is reached.