This document describes how to change a vDisk on multiple target devices without having to manually reconfigure them. It provides some general information about the process, then sets out a step-by-step procedure.
Setting vDisk Class and Type Properties
For an automatic update to take place, the Class of the target device and vDisk must match. For a newer vDisk to replace an older vDisk within a target device, the vDisk Class and Type of both vDisks must match. Because multiple, duplicate vDisk instances can exist within your implementation, and those vDisks can be assigned to one or more target devices (in the case of Provisioning Server Least Busy and First Available boot behaviors), you must further qualify the old vDisk that will be replaced by the new vDisk. This is the reason for using the Type property of the vDisk. If you want to use the Automatic Disk Image Update feature, you should never assign more than one vDisk with the same Type from the same Provisioning Server to the same target device.
Scheduling vDisk updates
To schedule when automatic updates can be applied, use the Apply vDisk updates as soon as they are detected by the server or Schedule the next vDisk update to occur on radio buttons on the Auto Update tab of the vDisk. If you select Schedule the next vDisk update to occur on, you must specify the current date or a later date, otherwise the vDisk will not be updated.
Timed update of vDisks
To do this, on one of the servers from each site create a Windows timer that calls the PowerShell Mcli-Run ApplyAutoUpdate command or the Mcli Run ApplyAutoUpdate command (see the PowerShell Administrator’s Guide or the MCLI Programmer's Guide for details). The command scans the site and updates all eligible vDisks that are configured to be updated. Because the command updates only those vDisks that need to be updated, the timer can execute every day and the updates are automatically made whenever new versions of vDisks are added.
Automatically adding a replacement vDisk
To automatically add a replacement vDisk to a site, place it in the store directory of the vDisk it replaces. When the update process is done, each store for the site is scanned for vDisks that are not defined in the site. If a vDisk is found that has the same Class and Type as an existing vDisk in the store directory, and its major, minor and build number is higher than the existing vDisk, it is automatically added to the site and assigned to target devices with matching Class.
The replacement vDisk must include all versions since and including the last merged base, or if no merged base exists, the base. All the VHD or VHDX, AVHD or AVHDX, and the PVP files for the versions included need to be placed into the store directory.
If the replacement vDisk has multiple versions, the manifest (XML) file needs to be included with the vDisk. To create the manifest file, perform a vDisk Export. To reduce the number of files that need to be delivered, delete obsolete versions in the vDisk Versions dialog before performing the vDisk Export.
To automatically update a vDisk
1. For the original vDisk, select the Auto Update tab, then set the following vDisk properties:
a. Enable automatic updates.
b. Select whether the update will be applied immediately or on a scheduled date when the check for updates is done or the Run ApplyAutoUpdate command is run.
c. Enter a Class and Type for the vDisk.
d. Enter a Major, Minor and Build number for the vDisk.
Note: The Serial Number field is set to a random Globally Unique Identifier (GUID) when the vDisk is created. It is for information only and you can edit it. It is not used for processing the Automatic Update.
2. For target devices that use the vDisk to be updated, select the General tab, then in the Target Devices Properties set the Class equal to the Class value of the original vDisk.
3. Ensure that the replacement vDisk is in the same store as the original vDisk.
4. For the replacement disk, select the Auto Update tab, then set the following vDisk properties:
a. Only enable automatic updates if this vDisk may later be replaced with another vDisk.
b. If automatic updates are enabled, select whether the update will be applied immediately or on a scheduled date when the check for updates is done or the Run ApplyAutoUpdate command is run.
c. Enter the same Class and Type that you entered for the original vDisk.
d. Enter a Major, Minor and Build number for the vDisk that is higher than the original vDisk.
5. If the vDisk update needs to be done in other farm sites, you can deliver and place the replacement vDisk setup described in step 4 in the same store as the original vDisk of the other farm site. This is described earlier in this document in ‘Automatically adding a replacement vDisk’.
6. Configure the update check. This will update any vDisks found with a higher Major, Minor, and Build number that are eligible to be updated. You can do this in either of the following ways:
· Right-click on the vDisk Pool, select the Check for Automatic Updates menu option, then click OK on the confirmation dialog.
· Set a timer as described earlier in this document.