[ovirt-users] difference between thin/depentend and clone/dependent vm virtual machine

Wed Apr 23 08:19:49 UTC 2014

I think that you are mixing up a lot of different things and to be 
honest I am not sure what configuration you have and what exactly you 
are trying to do.
so lets try to simplify it?
what type of storage are you working on?
which host is the spm?

On 04/22/2014 07:36 PM, Tamer Lima wrote:
> hello,
>
> I am in trouble
>
> I have 3 servers dedicated to test OVIRT:
> 01- engine + vdsm (8 cpus, 32GB ram , 2TB HD)
> 02 - vdsm (8 cpus, 32GB ram , 2TB HD)
> 03 - vdsm (8 cpus, 32GB ram , 2TB HD)
>
> I want to create cloned virtual machines but in my configuration I can 
> only save virtual machines on server 01; my configuration refers a 
> DATA DOMAIN on server 01
>
> All my virtual machines are : 2 cpu , 6 GB ram , 500gb HD and were 
> created like CLONE
>
> My server 01 is the data domain and all new virtual machine is 
> created, via NFS, on server 01 , who has 2TB maximum capacity ( the 
> same size of partition /sda3 = 2TB)
>
> how can I save each virtual machine on a desired vdsm server ?
>
> What I want is :
> server 01 - engine + vdsm : 03 virtual machines running and hosted 
> phisicaly on this host
> server 02 - vdsm : 04 virtual machines running and hosted phisicaly on 
> this host
> server 03 - vdsm : 04 virtual machines running and hosted phisicaly on 
> this host
>
> but I have this :
> server 01 - engine + vdsm : 03 virtual machines running and hosted 
> phisicaly on this host
> server 02 - vdsm : 01 virtual machines running on this server BUT 
> hosted phisicaly on server 01
> server 03 - vdsm : none, because my DATA DOMAIN IS FULL (2TB )
>
> How to solve this problem ?
> is it possible create one DATA DOMAIN for each VDSM host ? I think 
> this is the solution but I do not know how to point VMs to be saved on 
> specific data domain.
>
> thanks
>
>
>
>
> On Fri, Apr 18, 2014 at 4:48 AM, Michal Skrivanek 
> <michal.skrivanek at redhat.com <mailto:michal.skrivanek at redhat.com>> wrote:
>
>
>     On Apr 17, 2014, at 16:43 , Tamer Lima <tamer.americo at gmail.com
>     <mailto:tamer.americo at gmail.com>> wrote:
>
>     > hi, thanks for reply
>     >
>     > I am investigating what is and how "thin virtualization" works
>     >
>     > Do you know if HADOOP is indicated to work under "thin"
>     environment ?
>     > On Hadoop I will put large workloads and this thin
>     virtualization utilizes more resources than exists (shareable
>     environment)
>     > that is,
>     > if I have a real physical necessity of 500gb for each hadoop
>     host and my Thin Virtualization has 2TB on NFS, I can have only 4
>     virtual machines (500GB each), or less.
>     >
>     > For this case I believe clone virtual machine is the right
>     choice. But in my environment it takes 1h30m to build one cloned
>     virtual machine.
>
>     if you plan to overcommit then go with thin. The drawback is that
>     if you of course hit the physical limit the VMs will run out of
>     space...
>     if you plan to allocate 500GB each, consume all of it, never plan
>     to grow then go with the "clone"….yes, it's going to take time to
>     write all that stuff. With "thin" you need to do the same amount
>     of writes, but gradually over time while you're allocating it it
>
>     hope it helps
>
>     Thanks,
>     michal
>
>     >
>     >
>     >
>     > Am I correct ?
>     >
>     >
>     >
>     >
>     >
>     > On Thu, Apr 17, 2014 at 7:33 AM, Michal Skrivanek
>     <michal.skrivanek at redhat.com <mailto:michal.skrivanek at redhat.com>>
>     wrote:
>     >
>     > On Apr 16, 2014, at 16:41 , Tamer Lima <tamer.americo at gmail.com
>     <mailto:tamer.americo at gmail.com>> wrote:
>     >
>     > >
>     > >
>     > > Hello,
>     > >
>     > > I created VMs by two ways :
>     > >
>     > > 1) on tab virtual machines > new vm > template (centos_65_64bits)
>     > > 1.1 configuration : I do not select stateless checkbox
>     > > 1.2 this process takes a 1h30 to create each machine.
>     > >
>     > > 2) on tab pools > new vm > template (centos_65_64bits)
>     > > 2.1 default configuration : stateless
>     > > 2.2 Here I created 3 virtual machines at once
>     > > 2.3 this process takes only one minute
>     > >
>     > > On the tab virtual machines I can see all virtual machines.
>     > > Pooled machines have different icon image
>     > > and description is different too:
>     > >
>     > > machines generated from tab VM are described as clone/dependent
>     > > - clone is a phisical copy?
>     > > machines generated from tab POOL are described as thin/independent
>     > > - thin is a just a reference to template vm ? what is
>     phisical? any configuration file?
>     >
>     > yeah, sort of.
>     > just google thin provisioning in general:)
>     >
>     >
>     > >
>     > >
>     > > In practice, what is the difference between these machines ?
>     > >
>     > >
>     > >
>     > >
>     > > http://www.ovirt.org/Features/PrestartedVm
>     > > "Today there are 2 types of Vm pools:
>     > > • Manual - the Vm is supposed to be manually returned to the
>     pool. In practice, this is not really entirely supported.
>     > > • Automatic - once the user shuts down the Vm - it returns to
>     the pool (stateless)."
>     > >
>     > > all vm created from pool are stateless ?
>     >
>     > the automatic pool, yes
>     >
>     > Thanks,
>     > michal
>     >
>     > >
>     > >
>     > > thanks
>     > >
>     > >
>     > >
>     > > _______________________________________________
>     > > Users mailing list
>     > > Users at ovirt.org <mailto:Users at ovirt.org>
>     > > http://lists.ovirt.org/mailman/listinfo/users
>     >
>     >
>
>
>
>
> _______________________________________________
> Users mailing list
> Users at ovirt.org
> http://lists.ovirt.org/mailman/listinfo/users

-- 
Dafna Ron