There are several things to consider when planning for the deployment of an operating system image:
- Image Size
- Configuration Manager 2007 Client Cache
- State Migration Point and Distribution
- USMT package
- Advertisement Download Options
- Stand-alone Installation.
The size of an operating system image can be quite large, often 2GB or more. The size of the image will affect the performance and bandwidth utilization of the network. It is recommended that you test network performance to better gauge the affect that the image deployment might have and the time it will take to complete. Configuration Manager 2007 activities that affect network performance include distributing the image to a distribution point, distributing the image from one site to another, and downloading the image to the Configuration Manager 2007 client.
One way to mitigate excessive use of network bandwidth between Configuration Manager 2007 sites is to use Courier Sender to send image data from a parent Configuration Manager 2007 site to a child Configuration Manager 2007 site. Courier Sender uses physical media instead of sending data over the network. When you have large image packages that would require excessive time or bandwidth to send them over the network, this sender can be useful. You can use Courier Sender at the source Configuration Manager 2007 site to create a parcel (a collection of files transferred from one site to another using Courier Sender), write the parcel to a tape, CD, or other physical medium, and then ship the tape or CD to the destination site by mail or a courier service. At the destination site, you can then use Courier Sender to receive the parcel and import the package data into the site. Other information files associated with the image package are still sent using the existing network connection between the Configuration Manager 2007 sites.
It is also recommended that you plan for an appropriate amount of disk storage space on all targeted distribution points and branch distribution points. Keep in mind that a branch distribution point is often a client desktop computer, and that the size of the image can affect the computer's performance for the desktop user.
Consider the Client Cache Size
Configuration Manager 2007 clients automatically use Background Intelligent Transfer Service (BITS) if it is available. When you advertise a deployment task sequence, you can set an option on the advertisement so that Configuration Manager 2007 clients will download the full image to a local cache before starting to run it. If the distribution point is not local but has BITS enabled, BITS is used to download the image.
In general, when a package, or in this scenario an image, must be downloaded but the cache cannot accommodate the package, Configuration Manager 2007 checks the other packages in cache to determine whether deleting any or all of the oldest packages will free enough space to place the new package into the cache. If deleting any or all of the oldest packages does not free enough space, the new package is not placed into the cache.
This might be the case if there is a package that is currently locked. If deleting any or all of the oldest packages does free enough space in the cache, Configuration Manager 2007 does so, and places the new package into the cache.
The default cache size on Configuration Manager 2007 clients might not be large enough for most operating system image deployments. If you are planning to download the full image to a local cache before starting to run it, you must adjust the Configuration Manager 2007 client cache size on the destination computers to accommodate the size of the image you are deploying.
Users with administrative credentials on the computers they are using can manage the download cache. Users can change the size or location of the cache, or delete all current contents. These options are in the Temporary Program Download Folder section of the Advanced tab of the Configuration Manager item in Control Panel. The download cache can also be managed with scripts.
Configure State Migration Point and Distribution Point
If you are planning to migrate existing user and computer state settings as part of your image deployment, then you need to configure a state migration point to store the settings. You also need to consider the appropriate number and placement of distribution points that will host the image for Configuration Manager 2007 clients. For more information about planning for the state migration point and distribution points, see Planning ConfigMgr Site Systems for Operating System Deployment.
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There are basically two ways to run the image deployment on an Configuration Manager 2007 client computer. You can run the image by downloading it first to the Configuration Manager 2007 client cache from a distribution point and then installing it, or you can install the image from the distribution point. By default, when you create the advertisement for the deployment task sequence, the image is downloaded first to the Configuration Manager 2007 client cache and then installed. For more information about setting these options, refer to the Configuration Manager 2007 Operating System Deployment help topic Task Sequence - New Advertisement Wizard - Advanced Client.
If you choose to download the image to the Configuration Manager 2007 client cache before running it, and the deployment task sequence contains a step to re-partition the hard drive, the re-partition step will fail because re-partitioning the hard drive erases the contents of the Configuration Manager 2007 client cache. If the deployment task sequence must re-partition the hard drive, you must run the image installation from the distribution point using the Run program from distribution point option when the task sequence is advertised.
You can create stand-alone media to deploy the operating system manually to a destination computer. Configuration Manager 2007 Operating System Deployment supports the use of CD or DVD media. Again, the size of the image might affect your choice of stand-alone media. To create stand-alone media, run the Create Task Sequence Media Wizard from the Operating System Deployment node in the Configuration Manager 2007 Administrator's Console. For more information about running the Create Task Sequence Media Wizard, refer to the Configuration Manager 2007 Operating System Deployment help topic Task Sequence Media Wizard.
To deploy an operating system to a new computer that is not currently managed by Configuration Manager 2007, the new computer must be added to the Configuration Manager 2007 database prior to initiating the operating system deployment process. This is true whether or not the computer has an existing operating system. For more information about importing new computer information into Configuration Manager 2007, see How to Add a New Computer to the Configuration Manager Database.