Using Windows Stemcells
A “stemcell” is a customized operating system image containing the filesystem for BOSH-managed virtual machines. When deployed, it includes a process, the BOSH Agent, which is pre-configured to communicate with the orchestrating VM, the BOSH Director. The BOSH Agent is responsible for executing and monitoring “jobs” on the VM.
Deployments of Windows Server on PCF currently use a stemcell containing Windows Server 2012R2.
Note: Root disk sizing has been disabled and the default disk size for Windows cells has been increased. Future releases will provide ephemeral disk support to allow you to configure the size of your Windows cell.
The size of the root disk of a stemcell determines the minimum root disk size of any Windows VM that the BOSH Director can create from that stemcell. The relationship between the disk size of the stemcell and the root disk size of the Windows cells depends on your IaaS, as shown in the table below.
|IaaS||Windows Stemcell 1200.17+ disk size|
|vSphere||Recommended 128 GB+*|
The table bellow applies to Windows Stemcell 1200.16 and previous versions.
|IaaS||Stemcell root disk size||Possible root disk sizes for Windows cells|
|Azure||127 GB||127 GB|
|AWS||30 GB||30 GB or larger (for stemcell 1200.9 and later)|
|GCP||50 GB||50 GB or larger|
|vSphere||Recommended 128 GB+*||Same as stemcell minimum root disk size|
*Because you create your own stemcell on vSphere, you can control its root disk size. See Creating a vSphere Stemcell Manually for more information.
In the PAS for Windows 2012R2 tile > Resource Config pane, the VM types that you can choose from reflect the disk size constraints in the table above.
“Light” stemcells are metadata files used on a public IaaS that enable users to reference and deploy a stemcell without uploading it manually.
Below is the documentation currently available for activating light stemcells for the Runtime for Windows tile:
Below is the documentation currently available for building stemcells for the Runtime for Windows tile: