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

Dafna Ron dron at redhat.com
Wed Apr 23 13:21:56 UTC 2014


what do you mean that host1 is engine + vdsm, are you using hosted engine?



On 04/23/2014 01:59 PM, Tamer Lima wrote:
>
> hello,
> thanks for reply
>
> my storage is NFS v3, defined on host 01.  My DATA-DOMAIN and 
> ISO-DOMAIN are hosted on host 01;
> my SPM is located on host 03, I dont remember why. I tried to migrate 
> SPM to host 01 but is not possible. All creation of virtual machine 
> starts on server 01 (
>
>
>
>
>
>
> On Wed, Apr 23, 2014 at 5:19 AM, Dafna Ron <dron at redhat.com 
> <mailto:dron at redhat.com>> wrote:
>
>     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>
>         <mailto: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>
>             <mailto: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>
>         <mailto: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>
>             <mailto: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
>             > >
>             > >
>             > >
>             > > _______________________________________________
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>             > > Users at ovirt.org <mailto:Users at ovirt.org>
>         <mailto:Users at ovirt.org <mailto:Users at ovirt.org>>
>             > > http://lists.ovirt.org/mailman/listinfo/users
>
>             >
>             >
>
>
>
>
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>
>
>     -- 
>     Dafna Ron
>
>


-- 
Dafna Ron



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