Ops Manager Shows Compiled Releases Built Against a Different Stemcell Version Than the Assigned Tile Stemcell

Products

• VMware Tanzu Platform Core

Issue/Introduction

When deploying or upgrading a tile (for example TAS / Elastic Application Runtime):

• The tile is explicitly assigned a specific stemcell version in Ops Manager (for example ubuntu-jammy/1.866).

• Deployment VMs are correctly created using the assigned stemcell.

• However, release metadata, Ops Manager diffs, or deployment logs show releases or packages compiled against a different stemcell version (for example ubuntu-jammy/1.943), as indicated by:

  • exported_from metadata

  • release filenames

  • bosh inspect-release output

  • package compilation logs

This may raise concerns about stemcell mismatches or incorrect compilation.

Cause

This behavior is expected and results from how BOSH, Ops Manager, and tiles interact.

1. Ops Manager release inspection

Ops Manager does not recompile releases based on the stemcell assigned to a tile.

Instead, during staging and diff generation, Ops Manager:

• Uploads the release tarballs shipped with the tile

• Runs bosh inspect-local-release

• Displays the exported_from metadata embedded in the release

This metadata reflects the stemcell version used when the release was originally compiled, not the stemcell selected for VM deployment.

 

2. Precompiled releases in TAS / Elastic Application Runtime tiles

TAS / Elastic Application Runtime tiles ship with precompiled BOSH releases provided by Broadcom.

• These releases are compiled by the Broadcom against a specific ubuntu-jammy stemcell version.

• The stemcell version used for compilation is embedded in:

  • the release filename

  • the exported_from section of the release manifest

• This compilation stemcell is hard-coded in the tile and is independent of the stemcell assigned in Ops Manager.

Ops Manager stemcell assignment affects only the runtime VMs, not the release compilation metadata.

 

3. BOSH stemcell compatibility model

BOSH guarantees compatibility for compiled releases across:

• the same operating system (ubuntu-jammy)

• the same stemcell major version line (1.x)

As a result:

• A release compiled against ubuntu-jammy/1.943

• Is fully supported and valid on VMs running ubuntu-jammy/1.866

If multiple compatible stemcells exist in the Director, BOSH may also reuse or generate compiled packages against the newest available compatible stemcell for packages that are not precompiled.

Resolution

No action is required.

This behavior:

• does not indicate a misconfiguration

• does not mean the wrong stemcell is being used at runtime

• is fully supported by BOSH and Tiles

To confirm correct behavior:

• Use bosh vms --column stemcell to verify the runtime stemcell

• Use bosh inspect-release to verify which compiled release artifacts are in use

Additional Information

 

• Ops Manager diffs may change when tile versions are upgraded because newer tiles may ship releases precompiled against newer stemcells.

• Removing newer stemcells from the Director can influence which compiled packages are reused, but this is not recommended unless required for operational reasons.

• Exact stemcell version matching between compilation and runtime is not required and is not enforced by Ops Manager.