Assigning vDisks and versions to target devices
This article describes how vDisk version access modes relate to target device types, and how to assign and unassign a vDisk to a target device.
Accessing a version of the vDisk
Numerous differencing disk versions can exist for a vDisk. Device access to a particular version, or the ability to make updates to that version, depends on that versions access mode setting and the device type. The sections that follow describe the different version access modes and device types as well as their relationship to each other.
A version’s access mode is managed on the vDisk Versioning dialog. New versions of a vDisk are generally promoted from Maintenance to Test and then into Production. Access mode options include:
Maintenance – new read/write difference disk version that is only available to the first Maintenance device that selects to boots from it in order to make updates.
Test – read-only version used for test purposes and only available to Test or Maintenance devices.
Pending – read-only version and not yet available for use by Production devices because the scheduled release date and time has not been reached and/or the version it is not yet available to all servers in the site. If the Boot production devices from version drop-down list is set to Newest released, after the release date and time is reached and all servers are able to access this version, access changes to Default. If access displays as blank, this version is considered released to production, however it is not the version currently selected as the version from which Production devices should boot.
Default – read-only version that is bootable by all device types. If the Boot production devices from version is set to Newest released, then the latest released production version is marked with a green checkmark and the status is set to Default.
Override – read-only version that is bootable by all device types. If a specific version is selected from the Boot production devices from version drop-down list, then that version is marked with a green checkmark and the access changes to Override.
Newest released – read-only version that is bootable by all devices. If a specific version is selected from the Boot production devices from version drop-down list, then that version is marked with a green checkmark and the access changes to Override.
Merging – a merge is occurring to this new version. This version is unavailable to all device types until the merge completes. After the merge completes, the status of the new version depends on the Access mode selected on the Mode to set the vDisk to after automatic merge drop-down list (Production, Maintenance, or Test). This Farm Properties setting is available on the vDisk Versions tab.
The device Type is selected on the Target Device Properties General tab, unless it is an Update device, which is created automatically when the managed vDisk is created.
Device types include:
Maintenance devices can access any available version of a vDisk. A Maintenance device’s primary role is to manually update a vDisk. To do this, a new version is requested from the vDisk Versions Dialog, which creates a new read/write differencing disk and places that newly created version in Maintenance Access mode. While in Maintenance mode, this version of the vDisk can only be accessed by a single maintenance device (the first maintenance device that accesses it). Using that device, the vDisk is booted and any updates that are made are captured in the new differencing disk version. After updates are complete, the maintenance version can be promoted to Test mode or directly to Production mode.
In Maintenance Mode, a new version can also be created by merging existing versions into a new version or new base disk image.
While in Test mode, this version of the vDisk can only be streamed to Test or Maintenance devices to which it is assigned. This allows the new version to be tested before being released into the production environment, and permits Production devices to continue to stream from the previous version without interruption. If issues are found, this version can be reverted back into Maintenance mode.
If you are testing a device that uses a personal vDisk, use the assigned PvD Test device to test vDisk updates.
After successfully testing the new version, that version can be promoted to Production mode and made available to Product, Test, and Maintenance devices to which it is assigned. If issues are found, this version can be reverted back into either Test or Maintenance mode after any booted devices accessing this version are shut down.
If a device is assigned a personal vDisk, after the updated vDisk is tested using a PvD Test device, you can change the device to be a PvD production device, which allows you to continue testing for compatibility within your production environment.
- Update Devices
Update devices are used to update a Managed vDisk. Update Devices are created automatically when the Managed vDisk Setup Wizard is run. Only one Update device exists for each managed vDisk, and that vDisk and Update device are given the same name. For more information on Managed vDisks, refer to vDisk Update Management.
Unassigning vDisks from target devices
The Unassign from All site Devices option only unassigns vDisks that are not personal vDisks. When a personal vDisk is deleted, the vDisk’s Update Device is also deleted.
- Select the vDisk in the Console, then right-click and select the Unassign from Selected Device(s) or Unassign from All Site Devices menu option.
- If unassigning from select devices, in the Unassign from Devices dialog, select the devices to unassign to this vDisk, then click Unassign. If unassigning from all devices in a site, click Yes on the confirmation dialog that appears.
- After the target devices are successfully unassigned, close any open dialogs.
vDisk Versioning dialog
vDisk versioning is managed from the vDisk Versions dialog. To open the dialog, right-click on a vDisk in the Console, then select the Versions… menu option. The following provides a general description of the vDisk Versions dialog:
Boot production devices from version
From the drop-down box, select the version to use when booting target devices in production. The default is the newest version.
Version and status
This column lists versions and the current status of each version:
- Wrench icon indicates that this version’s access mode is set to Maintenance (read/write) mode, from which only a single maintenance device can boot.</span>
- Magnifying glass icon indicates that this version’s access mode is set to Test, from which only a test device can boot.</span>
- Clock icon indicates that this version’s access mode is set to Pending. A version that is Pending has been promoted to production but the release date and time have not yet been reached.</span>
- Green checkmark icon indicates that this version is the current production version based on settings selected on the Boot production devices from version drop-down menu. All device types can boot from vDisk version that is in production.
- Red X icon indicates that this version is obsolete, no devices are currently booted from it, and that this version can be deleted because a merged base was created, which is more current.
Provides the date and the time that this version was created. Date format is YYYY/MM/DD and time format is HH:MM
Provides the date and time that this version is scheduled to be released to production. The date format is YYYY/MM/DD and time format is HH:MM
The number of target devices streaming sessions for a given version.
Indicates target device access availability for a given version.
Maintenance read/write version that is available to the first maintenance device that selects to boots from it.
Test read-only version used for test purposes and only available to test or maintenance devices.
Pending read-only and not yet available for use because the scheduled release date and time has not been reached.
Default read-only version that is bootable by all devices. If the Boot production devices from version is set to Newest released, then the latest released production version is marked with a green checkmark and the access is set the Default.
Override read-only version that is bootable by all devices. If a specific version is selected from the Boot production devices from version drop-down list, the access changes to Override.
Merging a merge is occurring to this new version. This version is unavailable until the merge completes. After the merge completes, the status of the new version depends on the access mode selected on the Mode to set the vDisk to after automatic merge drop-down list (Production, Maintenance, or Test). The default Farm Properties setting is available on the vDisk Versions tab. A wrench icon is shown for merging version.
Blank, indicates that this version was released to production.
Identifies how the vDisk was created. The options include:
Manual created using Maintenance mode.
Automatic created automatically using an automated update.
Merge Created by a partial merge operation.
Merge Base Created by a base merge operation (no parent needed).
Base The original base image.
Creates a new maintenance version.
Opens a dialog that prompts to promote this version to Test or Production. If Production is selected, a release date and time can be set or the default (now) can be accepted.
Reverting from Test version: if no maintenance access version exists, revert moves latest test version into Maintenance.
Reverting from Production: any booted device will be shut down prior to reverting. Clicking Revert opens a dialog that allows the user to select to revert to Test or Maintenance.
Clicking Delete opens a delete confirmation dialog. Click OK to delete the selected version. Delete is only available if the latest version or obsolete version doesn’t have target devices currently booted from it.
Selecting a version, then clicking Replication opens the Disk Versioning Replication Status dialog. This dialog displays the replication status of this version on each server:
- Blue check next to the server name indicates that the version has been replicated on the server.
- Orange triangle next to the server name indicates that the version has not yet been replicated or there is an issue. Placing the cursor over the triangle will display the related error message.
To view the replication status of all versions of this vDisk on each server, right-click on the vDisk in the Console, then select Replication Status from the context menu.
Clicking on the Properties button opens the vDisk Version Properties dialog, which allows you to enter a description related to this version. It also displays availability of a selected version if that version is set for release to production in the future, or if no device has booted from that version yet.
The text box provides a description of the currently selected version.