I have two questions: 1) What does the master comilation job vm ( under the Resource config in the BOSH Director tile) exactly do ? - 2) What do the apply-add on Vms do ? What is their purpose.

[Dilip Krishnan]

-I also want to know what would happen if set the master compilation job vm count to 0 in the Resource config.

 

-I also want to know if there is a way to disable the creation of apply-add on VMs ( if it is possible).

I see this during the PKS tile installation.

Thanks!

[Daniel Lynch]

Some information regarding how and when a complication vm is used is documented here

https://bosh.io/docs/deploying-step-by-step/

 

Basically they are used to compile the software packages inside the release that is uploaded to bosh. These compiled images are then saved into the director blobstore (internal or external). So for every release that gets uploaded the compilation step should only need to run once.

 

If you set the compilation vms to 0 i suspect opsman will complain as that is not a supported config. But ultimately if you were able to do this then installing or upgrading to new software would fail. Keep in mind these VMs only exist when apply changes is running. They are deleted after the complication step of the deployment is completed.

 

 

I am not sure what you are referring to when you say "apply-add on VMs". From a bosh perspective an addon is a software package that you defined in "bosh runtim-config". It is an essential way to customize all of you deployed vms. Bosh director will apply all of your runtime configs even if you do not have any custom add-ons. Opsman does automatically setup some runtime configs for you. You can view them using "bosh configs" command.

https://bosh.io/docs/runtime-config/#addons

https://bosh.io/docs/addons-common/