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

Wed Apr 23 09:10:17 UTC 2014

Hi,

the solution for this would be either
use gluster or another shared storage
software across all 3 hosts
or go with local storage datacenters.

Am 22.04.2014 20:36, schrieb Tamer Lima:
> 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> wrote:
> 
>>
>> On Apr 17, 2014, at 16:43 , Tamer Lima <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> wrote:
>>>
>>> On Apr 16, 2014, at 16:41 , Tamer Lima <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
>>>> http://lists.ovirt.org/mailman/listinfo/users
>>>
>>>
>>
>>
> 
> 
> 
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