Publish a Virtual Machine - Advanced Detail

The following sections add detail about publishing a virtual machine (VM).

Published Virtual Machines

The first time a VM is published, a base image is created for that VM. Additional changes to the base image saved during each subsequent Publish action are maintained as a set of differencing disks. When a new version of a VM is published for deployment, only the changes since the last deployment need to be downloaded and added to the user's VM.

The NxTop Administrator can deploy any deployable, published, version of a VM.

The versions of a VM are listed under the name of the VM. The icon for the version includes a bar at the bottom that shows whether a version is deployable:

• The current main deployed version of the VM has a green bar; a VM has only one deployed version at a time.
• A version in staged deployment has an orange bar; it is distributed to selected users; a VM has only one deployed version at a time.
• Deployable versions have a blue bar.
• Non-deployable versions have a red bar.

The Versions tab on the Main panel for a VM tracks the version history:

The Versions tab lists the versions of the VM, whether it is deployable and which is the currently deployed version (Publish column), the version description, and the date it was created.

When a VM is published, the NxTop Administrator selects the type of version to publish:

• non-deployable - use this to save an interim point while working. The VM can be returned to this point if later changes are not satisfactory.
• deployable (but not deployed) - this is a version that is ready for use, but is not automatically distributed to assigned users. Use this to test a version before releasing it to users. It can be later deployed using the Deploy action on the version of the VM.
• staged - this is a version that is deployed to a selected users. Use this to release a version to selected users. See Staged Deployment for more information.
• deployed - this is the version to be distributed to assigned users (assigned the green bar)

A new VM must have a published version before it can be assigned to users.

Staged Deployment

You can also publish a staged version, that is, assign only a select number of users or groups to receive the version at a given time. For example, if you publish a new version for staged deployment, you can assign it to selected test users or groups. Only the selected users receive the new version. You can also used staged deployment to limit the number of users who can download the new version at any given time.

Staged deployment can be used to revert a limited number of users to a previous version (using the Deploy action). For example, if only two or three of one hundred users have a problem with an updated version of a VM, these two or three users can revert to a previous version using staged deployment - while the other 97 users can use the updated version. See Deploying a Virtual Machine for more information.

Reasons for staged deployment:

• Deliver a new version to a limited number of users for testing (can be done on Publish)
• Stage deployment of a new version of a VM to limit the number of downloads at any given time to avoid overwhelming I/O capacity. (for example, deploy to one quarter of your user population every six hours over the course of a day).
• If a new deployment is causing issues for a few users, stage the users with problems to a previous version. The users without problems can continue to use the updated version. When the problems are solved, those users can be reverted to the current version.

Reverting from Staged Deployment

After a staged deployment, you can cancel the staged state; assigned users revert to the current version of the VM. For example, if the test period is complete, or the issues were resolved for users that were staged back, you can end the staged deployment. You do this either by

• Selecting the staged version as the main version (all users then receive this version; it becomes listed as current in the list of versions)
• Undeploying the staged version (the staged users then receive the main version)
• If a VM with a staged version publishes a new version, you are offered a checkbox to reset users of the staged version to the new current versions.

See Deploying a Virtual Machine for details.

Publish Diagnostic Package

If a publish fails, or if the NxTop Administrator requests it for any publish, NxTop Center creates a publish diagnostics package tahth includes configuration and log data. This can be used by Customer Support to quickly diagnose and correct issues with your VM caused during publish.

1. The publish wizard includes a prompt:

   Diagnostics are always created in the case of a failure. Fill the checkbox to have diagnostics compiled in any case.

2. After the Publish task terminates, in the Tasks window, click the icon in the Task panel () to open the detailed information pop-up.
3. Click on the link (“Click here to retrieve publish diagnostics”).

   The diagnostic package for that Publish are compiled in a zip file. Click on the link to open or save the zip file. The zip file is named publishDiagnostics with a random number.

Click the link to open the zip file into a folder view. The component files can then be examined.