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

Tue Dec 18 06:35:43 PST 2012

Hi Gary,

this could be a solution, for me the best it would be to specify the 
system datastore which I want to put the VM.
Does anybody know if is possible to send a parameter to indicate this?, 
or will it be a new one feature?
Gary, is possible to have your driver, maybe it will be my solution....

Thanks,

;)riol

On 12/18/2012 03:09 PM, Gary S. Cuozzo wrote:
> Hi Oriol,
> I have deployed my own DS & TM drivers for my NFS & LocalFS datastores.  What they do is utilize mount points outside of the ONE directory and just symlink from the system datastore into the appropriate filesystem.  For example:
> /export/local/image1.img  (local disk mounted here)
> /export/san1/image2.img  (NFS mounted from SAN1)
> /export/san2/image3.img  (NFS mounted from SAN2)
>
> The drivers symlink into the system datastore to each of those images.
>
> This way, I am able to select the best of both worlds depending on the application.  Shared storage with live migrations, etc.  Or, local storage with high performance disk I/O.
>
> Thanks,
> 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: Tuesday, December 18, 2012 4:09:32 AM
> Subject: Re: [one-users] Two System Datafiles in the same cluster
>
> 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!
>>>
>