Enhancement: Reassign Instance to a Different ISO or Template

[scottsignal]

The required feature described as a wish

As a User I would like to unassign and reassign an instance to another ISO or template. It's not possible to guarantee a template will always be around and it's a waste of space to keep older templates. We have a need to update templates on a periodic basis.

[DaanHoogland]

@scottsignal , would you like users to be able to do this themselves? (hint: generally no ;) Would it make sense for there to be a “decendent” type structure for templates that would define what template to use in case of absence of the template. and then some auto assignment.
I see your pain, but am not feeling comfortable with (just) adding a templateid field to the updateVirtualMachine API.

[scottsignal]

@DaanHoogland I would say no to Users. But we don't use that type, so it doesn't affect our implementation. You probably have seen some of my other pain points around ISO/Templates because they don't follow hierarchy in the same way say Instances/Domains/Volumes do when an ISO/Template is set to Public.

[weizhouapache]

It's not possible to guarantee a template will always be around and it's a waste of space to keep older templates.

you can force-delete the template. the vm instances created from it will not be impacted.

the image of vm instance is created from a base image which is the template image.
if the vm instance is linked to another vm template which might cause some issues, for example

• the base image is removed from primary storage as ACS thinks the template is not used by vm instance
• volume migration might cause data corruption

[scottsignal]

It's not possible to guarantee a template will always be around and it's a waste of space to keep older templates.

you can force-delete the template. the vm instances created from it will not be impacted.

the image of vm instance is created from a base image which is the template image. if the vm instance is linked to another vm template which might cause some issues, for example

• the base image is removed from primary storage as ACS thinks the template is not used by vm instance
• volume migration might cause data corruption

What about just removing the association? Like a 1-way trip with a warning message that says this?

[weizhouapache]

It's not possible to guarantee a template will always be around and it's a waste of space to keep older templates.

you can force-delete the template. the vm instances created from it will not be impacted.
the image of vm instance is created from a base image which is the template image. if the vm instance is linked to another vm template which might cause some issues, for example

• the base image is removed from primary storage as ACS thinks the template is not used by vm instance
• volume migration might cause data corruption

What about just removing the association? Like a 1-way trip with a warning message that says this?

the 2nd issue might not occur, but the 1st issue might still exist.

I think the safe way for now is, force-deleting the template. templates will be removed from secondary storage, vms are not impacted. when vms is expunged or reinstalled, ACS will clean up the unused template image on primary storage.

[scottsignal]

It's not possible to guarantee a template will always be around and it's a waste of space to keep older templates.

you can force-delete the template. the vm instances created from it will not be impacted.
the image of vm instance is created from a base image which is the template image. if the vm instance is linked to another vm template which might cause some issues, for example

• the base image is removed from primary storage as ACS thinks the template is not used by vm instance
• volume migration might cause data corruption

What about just removing the association? Like a 1-way trip with a warning message that says this?

the 2nd issue might not occur, but the 1st issue might still exist.

I think the safe way for now is, force-deleting the template. templates will be removed from secondary storage, vms are not impacted. when vms is expunged or reinstalled, ACS will clean up the unused template image on primary storage.

I just hate the idea of having to force delete the template/ISO and then turn around and upload the same template over just so it can be reassigned. So essentially, every time we provision an instance on behalf of a customer using a Template/ISO that cannot be exposed to a customer we would have to do this.