Introducing WinPE Peer Cache

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WinPE Peer Cache is a new feature of SCCM CB 1610. It functions in a similar manner to BranchCache however, it is only available for content access from the Windows Preinstallation Environment (WinPE). WinPE Peer cache is configured and managed as part of the SCCM CB client management settings.

A task sequence configured to use Windows PE Peer Cache can get the following content objects from a local peer while running in Windows PE:

  1. Operating system image
  2. Driver package
  3. Packages and Programs (When the client continues to run the task sequence in the full operating system, the client gets this content from a peer cache source if the task sequence was originally configured for peer cache when running in Windows PE.)
  4. Additional boot images

It is important to understand that WinPE Peer Cache is targeted at OSD scenarios and does not replace Distribution Points and BranchCache as locations for other types of content. For example, the following content objects never transfer using peer cache. Instead, they transfer from a distribution point or by Windows BranchCache if you have configured Windows BranchCache in your environment:

  1. Applications
  2. Software updates

WinPE Peer Cache only supports OSD scenarios that include a WinPE boot such as PXE boot or Boot Media.

WinPE Peer Cache is very new and is evolving very rapidly. To avoid possible issues with the model, Microsoft is adding features to create higher deployment success rates. Beginning with SCCM CB 1702, a peer cache source computer will reject a request for content when the peer cache source computer meets any of the following conditions:

  1. Is in low battery mode.
  2. CPU load exceeds 80% at the time the content is requested.
  3. Disk I/O has an AvgDiskQueueLength that exceeds 10.
  4. There are no more available connections to the computer.

One thought on “Introducing WinPE Peer Cache

    Damon Wilson said:
    March 18, 2019 at 10:29 am

    Can the clients pull the boot image from the peer cache host when they pxe against the remote distribution point? Strangely enough, while my packages are being preserved on the host peer via SMSTSPreserveContent, for some reason the boot image is not persisting (none of my packages are set to persist content in client cache). As a test I have set it to download it during the host peer cache TS, and while I now see it in the host machine cache, new pxe clients don’t seem to use it. Perhaps this is not possible as all the documentation states that peer cache works with “Additional boot images”. So does that mean it does not work with the boot image the TS actually uses? My issue is that at some of our sites the boot image can take hours to download so I am trying to see if they can pull it locally rather than standing up a DP at that site. If not, I assume my only option is to have those clients use bootable media to start the process. Any light you could shed on this issue would be appreciated. I am running SCCM 1810. Thanks.

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