So you essentially want to just deploy a new VM based on a template with a thin provisioned disk ? 

When you create your VM based on the template check in advanced options – Resource allocation and see if the option there for template provisioning is set to clone or to thin provision. Clone in your case I believe would create a 40GB image file based on the template whereas thin provision will create you a thin provisioned disk just using the same actual data amount as the thin provisioned template. I’m pretty sure you can only do this if your template disk is thin (not preallocated) provisioned.

Darren Hart | IT Manager | Department of Biochemistry | University of Otago

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From: Punit Dambiwal <hypunit@gmail.com>
Date: Wednesday, 27 August 2014 1:18 pm
To: Michal Skrivanek <michal.skrivanek@redhat.com>
Cc: "ahadas@redhat.com" <ahadas@redhat.com>, "users@ovirt.org" <users@ovirt.org>
Subject: Re: [ovirt-users] VM Deployment By Template

Hi Michal,

I want to deploy the VM with the template but the problem is in ovirt when you deploy the VM by template it copy the whole image(even thin or thick disk)...like if i have 40GB virtual size (actual size 1GB) disk....it will copy the whole 40GB to provision the virtual machine....so if i want to deploy 10 VM simultaneous then it will copy 4TB data and take long time to provision....

I want the way i can make the template with small size....and once i choose to create the virtual machine with 40GB...the VM deploy with the small template on the 40GB disk... is it possible with ovirt.. ??

Thanks,

Punit 

On Tue, Aug 26, 2014 at 9:01 PM, Michal Skrivanek <michal.skrivanek@redhat.com> wrote:

On Aug 26, 2014, at 12:01 , Punit Dambiwal <hypunit@gmail.com> wrote:

> Hi Michal,
>
> 2. I find disk size can not modify at the time of VM provisioning,is there any way to modify the VM disk size ??
>
> well, not really, AFAIK.
> create another disk, move your data, remove the original Or create a bigger thin provisioned disk at the beginning...
>
> I didn't understand the mean...i can create the another disk...it's ok...but how to move the data from the existing disk to new disk at the time of the VM deployment... ?? is there any way to move the data.. ??

Hi,

You would have to do that inside the guest…the same way as you would do it on real hardware…mount both disks, move the relevant data
not trivial and not automated

>
> Another question is there any way to mount the img like i will create the VM with blank template with my preferred disk size and leter on install the OS through any OS template ??? i know i can install the OS through CD-ISO but i don't want the manual installation…

so you want to have a preinstalled OS…so how did you want to use it?
I probably don't understand what are you trying to achieve.
Anything else than having a Template with OS and you deploy VMs from that….you need to change disk sizes for each such VM? Could it be done by adding an additional disk?

Thanks,
michal

>
> Thanks,
> Punit
>
>
> On Tue, Aug 26, 2014 at 5:51 PM, Michal Skrivanek <michal.skrivanek@redhat.com> wrote:
>
> On Aug 26, 2014, at 05:26 , Punit Dambiwal <hypunit@gmail.com> wrote:
>
> > Hi All,
> >
> > I have some questions regarding the VM deployment through OS template...
> >
> > 1. I have imported centos template from openstack glance (the actual size of the template is 16GB but used is 1GB)...now my question is if i deploy the new VM with this template,the process will copy the whole 16GB or just 1 GB to create the new VM ??
>
> if you deploy with thin provisioned disks it should be 1GB
>
> >
> > 2. I find disk size can not modify at the time of VM provisioning,is there any way to modify the VM disk size ??
>
> well, not really, AFAIK.
> create another disk, move your data, remove the original.
> Or create a bigger thin provisioned disk at the beginning
>
> >
> > Thanks,
> > Punit
> >
> >
> > On Mon, Aug 25, 2014 at 5:42 PM, Punit Dambiwal <hypunit@gmail.com> wrote:
> > Hi All,
> >
> > I have some questions regarding the VM deployment through OS template...
> >
> > 1. I have imported centos template from openstack glance (the actual size of the template is 16GB but used is 1GB)...now my question is if i deploy the new VM with this template,the process will copy the whole 16GB or just 1 GB to create the new VM ??
> >
> > 2. I find disk size can not modify at the time of VM provisioning,is there any way to modify the VM disk size ??
> >
> > Thanks,
> > Punit
> >
>
>