[Users] Templates and originating VM relationship

2013-03-26 Thread Gianluca Cecchi
Hello,
oVirt 3.2.1 on Fedora 18.
I customize a CentOS 6.4 VM and when I comfortable I select make template.
I don't take any snapshot for the VM before this.

I thought that VM would have been disappeared, transforming itself
into a template, instead at the end I have both the template and the
originating VM.
Apparently with the same name for the disk and the same storage domain

What is exactly the relationship between them?
Can I safely remove the originating VM?

I already tested making template and then deleting it and then being
able to power on again VM and make a new template from the originating
VM.

The rhevm 3.1 admin manual is not so clear about this: it contains a
note regarding

Take a snapshot of the virtual machine at this stage if you wish to
use the virtual machine
(as a virtual machine) after using it to create a template.


But if behavior of oVirt 3.2.1 has to be the same with it, this
doesn't explain itself based on my experience

Thanks in advance for any information

Gianluca
___
Users mailing list
Users@ovirt.org
http://lists.ovirt.org/mailman/listinfo/users


Re: [Users] Templates and originating VM relationship

2013-03-26 Thread Koch (ovido)
Hi Gianluca,

@oVirt-team: please correct me if I misunderstood something on the
template-concept...

Unlike Vmware (which converts a vm into a template) RHEV/oVirt is
copying the vm into a template.

So you can remove or edit your original vm without having an impact on
your template.

More important is the template provisioning method when creating vms
from your template. If you choose Thin, only changes between your
template and your vm are written to your vms disk file, where clone
creates a clone of your template's disk. Template thin provisioning
saves disk space, but you can't delete the template as long as you don't
delete all vms linked to this template.

The name of your disk is just a name (and it seems that it doesn't have
to be unique) - important is the ID, which is used by oVirt internally.


Regards,
René




On Tue, 2013-03-26 at 15:11 +0100, Gianluca Cecchi wrote:
 Hello,
 oVirt 3.2.1 on Fedora 18.
 I customize a CentOS 6.4 VM and when I comfortable I select make template.
 I don't take any snapshot for the VM before this.
 
 I thought that VM would have been disappeared, transforming itself
 into a template, instead at the end I have both the template and the
 originating VM.
 Apparently with the same name for the disk and the same storage domain
 
 What is exactly the relationship between them?
 Can I safely remove the originating VM?
 
 I already tested making template and then deleting it and then being
 able to power on again VM and make a new template from the originating
 VM.
 
 The rhevm 3.1 admin manual is not so clear about this: it contains a
 note regarding
 
 Take a snapshot of the virtual machine at this stage if you wish to
 use the virtual machine
 (as a virtual machine) after using it to create a template.
 
 
 But if behavior of oVirt 3.2.1 has to be the same with it, this
 doesn't explain itself based on my experience
 
 Thanks in advance for any information
 
 Gianluca
 ___
 Users mailing list
 Users@ovirt.org
 http://lists.ovirt.org/mailman/listinfo/users

___
Users mailing list
Users@ovirt.org
http://lists.ovirt.org/mailman/listinfo/users


Re: [Users] Templates and originating VM relationship

2013-03-26 Thread Gianluca Cecchi
On Tue, Mar 26, 2013 at 3:41 PM, René Koch (ovido)  wrote:

 Unlike Vmware (which converts a vm into a template) RHEV/oVirt is
 copying the vm into a template.

 So you can remove or edit your original vm without having an impact on
 your template.

OK.
So the note in Procedure 9.1 at page 162 of RHEV 3.1 admin guide is
not correct


 More important is the template provisioning method when creating vms
 from your template. If you choose Thin, only changes between your
 template and your vm are written to your vms disk file, where clone
 creates a clone of your template's disk. Template thin provisioning
 saves disk space, but you can't delete the template as long as you don't
 delete all vms linked to this template.

This was clear to me based on manual contents, but thanks for the remainder.

Gianluca
___
Users mailing list
Users@ovirt.org
http://lists.ovirt.org/mailman/listinfo/users


Re: [Users] Templates and originating VM relationship

2013-03-26 Thread Koch (ovido)

On Tue, 2013-03-26 at 15:50 +0100, Gianluca Cecchi wrote:
 On Tue, Mar 26, 2013 at 3:41 PM, René Koch (ovido)  wrote:
 
  Unlike Vmware (which converts a vm into a template) RHEV/oVirt is
  copying the vm into a template.
 
  So you can remove or edit your original vm without having an impact on
  your template.
 
 OK.
 So the note in Procedure 9.1 at page 162 of RHEV 3.1 admin guide is
 not correct

I didn't had issues when creating templates from vms without snapshots
and reusing the vm again.

I think it's because of sealing/sysprep.

Let's assume you create a template of a windows vm, I would do the
following steps:
1. Install all apps and settings in your vm
2. Take a snapshot of this vm
3. sysprep your vm
4. Create a template
5. Revert to previous snapshot when reusing your vm, as otherwise
sysprep would start (and you don't want it for your master-image).



 
 
  More important is the template provisioning method when creating vms
  from your template. If you choose Thin, only changes between your
  template and your vm are written to your vms disk file, where clone
  creates a clone of your template's disk. Template thin provisioning
  saves disk space, but you can't delete the template as long as you don't
  delete all vms linked to this template.
 
 This was clear to me based on manual contents, but thanks for the remainder.
 
 Gianluca

___
Users mailing list
Users@ovirt.org
http://lists.ovirt.org/mailman/listinfo/users