Re: Ephemeral Disk Support for Windows 1709 and Windows 1803 Stemcells

Mike Lloyd <mike@...>



From: cf-dev@... <cf-dev@...> On Behalf Of Amit Kumar Gupta
Sent: Thursday, September 20, 2018 1:35 PM
To: cf-dev@...
Subject: Re: [cf-dev] Ephemeral Disk Support for Windows 1709 and Windows 1803 Stemcells




Couple ideas:

- might want to consider cross posting to cf-bosh as well if you weren’t already planning to

- if there are high level outcomes this improves, like deploy speed, upgrade speed, security (disk encryption?), or anything like that in addition to Ubuntu  parity, that’d be awesome to call out as well


Cheers, congrats on shipping this!




On Thu, Sep 20, 2018 at 12:29 PM Kartik Lunkad <klunkad@...> wrote:

Hi all,

We are rolling out Ephemeral Disk Support for the Windows Server, version 1709-based stemcells as well as Windows Server, version 1803-based stemcells! You can find them on


What is this feature? 

This feature will allow you to have a much smaller root disk footprint, and allow you to use ephemeral disk for your applications! We have now reduced the root disk to be 30GB. 


What versions? 

You should find this feature in the 1709.13+ and 1803.2+ stemcells! 



The minimum ephemeral disk size should be 30GB. You could configure your ephemeral disk based on your applications' needs. Our recommendation would be to have at least a 100GB ephemeral disk size. 


How to use it? 

You can utilize this feature just the way you've done with Linux previously with setting vm_types/vm_extensions in your cloud config. Once you've done that, you can then use that in your deployment manifest!


Example - 

Cloud Config Example

- name: 100GB_ephemeral_disk
    disk: 51200 

Deployment Manifest Example

- name: windows1709
  instances: 1
  vm_type: default
  stemcell: windows
  vm_extensions: [100GB_ephemeral_disk]


The BOSH Windows team have worked hard to enable this functionality. Please do provide us feedback on it! 




Kartik Lunkad

Senior Product Manager

Pivotal  ::

email: klunkad@...

mobile: 4129614215

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