MODULE 3: OS & APP LAYERS
Agenda
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Preparing and importing a gold image
Creating and understanding Install Machines
Creating basic Application layers
Understanding what is captured in an App
Layer
• Layer Priority and conflict resolution
• Updating layers
Module 3
IMPORTING A GOLD IMAGE INTO
AN OS LAYER
Terminology
• Gold Image = The VMware Virtual Machine built that
contains the base operating system you will import
into a Unidesk OS Layer.
• OS Layer = Operating System layer stored in Unidesk
format and managed by Unidesk. No association with
the original gold image.
• Application Layer = Independent layers created
based on specific OS layers. Can contain anything, an
application, individual files, registry entries, service
states, etc.
Basic Steps in Creating an OS Layer
• Create a Windows VM in vCenter
• Prepping the Gold Image for import
– Disabling certain Items, “tuning” the OS, etc
• Create the Unattend.xml answer file
– Our scripts to c:\windows\setup\scripts
• Install Unidesk drivers
• Import the OS into Unidesk
•
Pro-tip: if you are new to this, create a VMware snapshot prior to configuration to
allow you to rollback if you make a mess of the setup 
OS Layer Key Concepts
• Each desktop built has a single OS Layer, version may
change, OS may be updated, OS Layer stays the
same.
• Desktop Build Automation is based on Windows
mini-setup being invoked during build. Unattend.xml
drives the automation for basic Windows settings.
• Setupcomplete.cmd is a MS script that runs post
build for additional configuration/customizations to
occur.
Understanding Desktop Build Steps
Desktop Build initiated- Blank Personalization Layer
• Unidesk driven and calls vCenter to handle basic tasks like Create a VM, attach disk,
Power on VM, etc
Mini-setup runs, getting its setting from unattend.xml
• Runs only once for any machine – Unidesk desktops are not destroyed
• Domain to join
• OU to place the VM
• Licensing Information
SetupComplete.CMD runs POST mini-setup
• This may contain licensing activation
• Calles to apply a GPOs from the domain
• Application scripts
• Any post build customization you may want to do
Creating the Gold Image
• Unidesk supports Win 7 32 or 64 bit and 32 bit
Windows XP
• Disk size and type during creation doesn’t matter as
the import process only grabs file system contents
and does not copy the VMDK at all
• Install VMware tools, Disable System Restore & turn
off Windows auto-updates
– Auto-updates can be re-enabled when updating the gold
image. Or can be manually initiated.
lab
PREP THE GOLD IMAGE
Unattend.xml creator
• Copy the tools into
the Setup\Scripts dir
first
• Use ‘Run as
administrator’
• Will report errors if
you cannot save to
the proper locations
lab
DOWNLOAD TOOLS AND RUN
UNATTEND.XML CREATOR
Optimizer Tool
• Created by the
Unidesk Solution
Team
• Allows for you to pick
and choose
optimization
• Use intelligently!
Some tuning hurts
applications!
Installing the Unidesk Drivers
• Installs our drivers, and registers with the Unidesk
Management Appliance
• Registration allows for Unidesk to be aware of the
gold image for import tasks
• Run as administrator
• Do not run from a share
• Will request the DNS name/IP of the Unidesk
Management Appliance
Creating the OS Layer
• Running the “Create OS layer” wizard starts
the process
• Know your Gold Image VM name as seen in
vCenter
• Layer name and version info in the wizard can
be changed later. The key is to get the import
running.
• Import may take between 7 and 20 minutes
depending on hardware.
lab
INSTALLING THE DRIVERS AND
IMPORTING THE OS LAYER
Post Import
• Test Deployment of desktop with just the OS
layer
• Validate Domain Join and other functions from
automated setup function properly
• Add versions to the OS layer to make
adjustments to the unattend.xml, scripts or
anything else OS related. No need to reimport.
INSTALLATION MACHINES
Install Machines
• Install Machines are a staging area for the
creation of app layers and for adding versions
to app layers and OS layers
• There are VMs with no “hard drive” that are
created specifically for the app layer or OS
layer being created or versioned
• Think of IMs as automatically created and
refreshed packaging machines!
Install Machines
lab
CREATING INSTALLATION
MACHINES
Building an app layer
App layer (all writes go here)
O/S layer (read-only)
C:\DIR\A.DAT
C:\DIR\B.DAT
C:\DIR\C.DAT
• A new, empty app layer is created
– Or, when doing updates/patches, the prior copy of the layer
Building an app layer
C:\DIR\D.DAT (new file)
(copied and then modified)
Delete C:\DIR\C.DAT (marks C.DAT as deleted)
App layer (all writes go here)C:\DIR\B.DAT
O/S layer (read-only)
C:\DIR\A.DAT
C:\DIR\B.DAT
C:\DIR\C.DAT
• A new, empty app layer is created
– Or, when doing updates/patches, the prior copy of the layer
• Any data that is written (directories, files, keys, …) is stored in the new
layer
• Files in the O/S layer that are modified are first copied to the app layer,
and then modified
Building an app layer
Resulting C:
C:\DIR\A.DAT (from O/S)
C:\DIR\B.DAT (from App)
(C:\DIR\C.DAT removed by App)
C:\DIR\D.DAT (from App)
C:\DIR\D.DAT (new file)
(copied and then modified)
Delete C:\DIR\C.DAT (marks C.DAT as deleted)
App layer (all writes go here)C:\DIR\B.DAT
O/S layer (read-only)
C:\DIR\A.DAT
C:\DIR\B.DAT
C:\DIR\C.DAT
• A new, empty app layer is created
– Or, when doing updates/patches, the prior copy of the layer
• Any data that is written (directories, files, keys, …) is stored in the new
layer
• Files in the O/S layer that are modified are first copied to the app layer,
and then modified
Lab
CREATING A BASIC APP LAYER
App Layering Pro Tips
• Reduce desktop (File system) change during install
– Don’t copy installer locally unless required
– Install from a share or ISO
– This will keep package size to a minimum
• On the Administrator Profile leave a shortcut to your Install
Media Share
• User Changes are caught in current user’s profile, NOT
deployed to the user
– Use GPO/GPP or simple script to deploy User based
application changes
• MS Products license together (like MS Office and Visio)
use Office as a prerequisite layer any time creating a
layer for other “Office” products
LAYER PRIORITIES AND CONFLICTS
Layer Priority Rules
• All Layers are “stacked” in a priority order
• Personalization layer always wins (unless you
override)
• OS layer is always on the bottom of the stack
• Layer priority within the application stack
based on package creation date and time
– MSI installer rules during install are followed- key
to understand pre-requisite layers
Layer Priority Example
Results within desktop:
• Layers Stacked based
on internal priority
numbering system
• Can override priorities
system wide
• Personalization layer
override done on an
app by app basis
C:\DIR\A.DAT
C:\DIR\B.DAT
C:\DIR\C.DAT
C:\DIR\D.DAT
from
from
from
from
App layer 1
C:\DIR\A.DAT
C:\DIR\B.DAT
App layer 2
C:\DIR\B.DAT
C:\DIR\C.DAT
O/S layer
C:\DIR\C.DAT
C:\DIR\D.DAT
APP1
APP1
APP2
OS
Layer Priority Example
Results within desktop:
• Layers Stacked based
on internal priority
numbering system
• Can override priorities
system wide
• Personalization layer
override done on an
app by app basis
C:\DIR\A.DAT
C:\DIR\B.DAT
C:\DIR\C.DAT
C:\DIR\D.DAT
from
from
from
from
App layer 2
C:\DIR\B.DAT
C:\DIR\C.DAT
App layer 1
C:\DIR\A.DAT
C:\DIR\B.DAT
O/S layer
C:\DIR\C.DAT
C:\DIR\D.DAT
APP1
APP2
APP2
OS
Layer Priority Screen
Lab
CHANGING LAYER PRIORITY
Layer Storage
• Stored in VDMK format
• All Layers start life on the Master CachePoint
datastore
• Layers are replicated to other CPs/datastores
based on desktop layer assignments
• Layer versions are all stored in the same
directory under the layer name in the
datastore
Lab
VIEWING LAYERS ON THE DATASTORE
VERSIONING APP AND OS LAYERS
Updating an Existing Layer
C:\DIR\D.DAT (new file)
(copied and then modified)
Delete C:\DIR\C.DAT (marks C.DAT as deleted)
App layer (all writes go here)C:\DIR\B.DAT
O/S layer (read-only)
C:\DIR\A.DAT
C:\DIR\B.DAT
C:\DIR\C.DAT
• Original App Layer is copied on the MCP datastore
• This copy is mounted to the IM and the admin updates the existing layer
• Any data that is written (directories, files, keys, …) is stored in this copy
Lab
VERSIONING A LAYER
Swapping Layers vs Versioning
• You also have the ability to create a NEW layer
instead of versioning a layer
• Key difference in swapping is that the
personalization layer is “cleaned up” of any
application conflicts from the “old” layer.
• This is often used for Agents and other mgmt
or IT type software
QUESTIONS YOU MAY SEE AGAIN
Review Questions
• What desktop operating systems does Unidesk
2.1 support?
• During installation of the Unidesk drivers the
installer asks for the IP or DNS name of what
piece of infrastructure?
• When creating a new version of a layer what
happens to the existing (current) version?
• What do you edit/create to modify which
domain or OU new desktops join to?