[one-users] Two System Datafiles in the same cluster

Tue Dec 18 01:23:14 PST 2012

Hi Oriol,

I guess you're right, I had a few problems with disk speed (small block
size) and I tested other disk:
- mounted the disk on /mnt/new_disk
- copied the image.raw and image.qcow2 to new disk
- created new Datastore (ID=100) and new symbolic link on
.../datastores/100 pointing to /mnt/new_disk
- registered new images on Opennebula specifying datastore 100
- updated template
- instantiated new VMs
 This allowed me to test the new disk with better results, but I guess it
would be extremelly useful to input on REQUIREMENTS var the wanted
datastore.

--
André Monteiro

On Tue, Dec 18, 2012 at 9:09 AM, Oriol Martí <omarti at cesca.cat> wrote:

> Hi Gary,
>
> I've read the docs, but I think I'm not understanding something, when you
> create vm's all the images are copied in the /var/lib/one/datastores/0,
> then all your virtual machines are running from an NFS system datastore and
> it's impossible to run the virtual machines from local storage....
> Have you tried to create virtual machines from different datastores and
> see if the disk speed is really different?
>
>
> On 12/17/2012 06:37 PM, Gary S. Cuozzo wrote:
>
>> I do exactly what you reference below, use NFS for shared storage and
>> also localfs for high performance local storage.  But, I only have 1 system
>> datastore.  When you use shared storage such as NFS or iSCSI, the system
>> datastore also has to be shared.  I think the system datastore is typically
>> datastore ID 0.  That's what it is in my system as it's created by ONE.
>>
>> In your case, you will need to share the system DS to each host in the
>> cluster.  For example, I have /var/lib/one/datastores/0 NFS exported from
>> ONE controller to each vm host and mounted there in the same place.
>>
>> Then, you just use each other DS as you wish and ONE handles copying,
>> linking, etc as needed.
>>
>> Hope that makes some sense.  Read up on the storage docs, they are very
>> good as describing all this.
>>
>> gary
>>
>>
>> ----- Original Message -----
>> From: "Oriol Martí" <omarti at cesca.cat>
>> To: "Gary S. Cuozzo" <gary at isgsoftware.net>
>> Cc: "Users OpenNebula" <users at lists.opennebula.org>
>> Sent: Monday, December 17, 2012 12:17:47 PM
>> Subject: Re: [one-users] Two System Datafiles in the same cluster
>>
>> Hi Gary,
>>
>> thank you for your fast response,
>> my idea is to have an NFS and a local datastore, which are system
>> datastores, to store the images of the running vms. Then you can create
>> vms with faster disk (local) or slower disk (NFS). I've tried to have
>> two systems datastores in the same cluster and it's possible.
>>   From what I understood, when you create a vm, the image is copied from
>> the image datastore to the default system datastore, which you define in
>> the cluster as SYSTEM_DS. I don't know if its possible to create a vm in
>> a different datastore than the cluster's default.
>>
>> I don't know if I'm missing something about the copy process or
>> something.... Basically I would like to decide, when I create a vm, to
>> give it faster or slower disk depending on what I need. In my point of
>> view I think that if you use image datastores faster, you only will take
>> advantage of the speed when is copying, one time copied it's going to be
>> slower if its copied in a slower NFS datastore.
>>
>> Best regards,
>>
>>
>> On 12/17/2012 04:42 PM, Gary S. Cuozzo wrote:
>>
>>> Hello Oriol,
>>> I don't think you can have more than one system datastore, but I could
>>> be wrong about that.  But, unless I misunderstand your goal, I don't think
>>> you need to have more than one.  You should simply be able to define 2
>>> datastores and associate each with the cluster.  I have a similar setup to
>>> what you describe, I have a cluster that has 2 different NFS datastores, a
>>> local file datastore, and an iSCSI datastore.  I can use images from
>>> any/all datastores in a single vm (though I actually don't).
>>>
>>> Hope that helps,
>>> gary
>>>
>>>
>>> ----- Original Message -----
>>> From: "Oriol Martí" <omarti at cesca.cat>
>>> To: users at lists.opennebula.org
>>> Sent: Monday, December 17, 2012 9:53:43 AM
>>> Subject: [one-users] Two System Datafiles in the same cluster
>>>
>>> Hi,
>>>
>>> somebody knows if it is possible to have two system datastores in a
>>> cluster and create VM in the same host but in different datastores?
>>> I've my default SYSTEM_DS="101" in the cluster, I've tried to add to the
>>> MV template to change the datastore which the vm is created:
>>> REQUIREMENTS= "DATASTORE_ID = \"103\""
>>> (I don't know if this is correct)
>>>     But the VM does not boot, and is in pending state. Somebody know if
>>> is possible or I have to create two clusters one with the datastore 101 and
>>> another one with the datastore 103?
>>>
>>> My idea is to have one cluster with one NFS datastore and another
>>> local-file datastore.
>>>
>>> Thanks!
>>>
>>>
>>
>
> --
>
> ..............................**..............................**..........
>          __
>         / /          Oriol Martí Bonvehí
>   C E / S / C A      Administrador de Sistemes
>       /_/            Centre de Supercomputació de Catalunya
>
>   Gran Capità, 2-4 (Edifici Nexus) · 08034 Barcelona
>   T. 93 551 6212  · F.  93 205 6979 · omarti at cesca.cat
> ..............................**..............................**..........
>
> ______________________________**_________________
> Users mailing list
> Users at lists.opennebula.org
> http://lists.opennebula.org/**listinfo.cgi/users-opennebula.**org<http://lists.opennebula.org/listinfo.cgi/users-opennebula.org>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.opennebula.org/pipermail/users-opennebula.org/attachments/20121218/2eff0b43/attachment-0002.htm>