[one-users] opennebula 3.8.1 + clvm

[Marlok Tamás]

sorry, accidentally pressed "Send" button. This is not the final mail :)

Cheers,
tmarlok


On Tue, Mar 12, 2013 at 12:22 PM, Marlok Tamás <tmarlok at sztaki.hu> wrote:

> Hi Jaime,
>
>
> On Tue, Mar 12, 2013 at 12:16 PM, Jaime Melis <jmelis at opennebula.org>wrote:
>
>> Hi Marlok,
>>
>> I agree with what you said, it would be much better to remove the
>> requirement of CLVM, but I have a couple of concerns.  Let's see if we can
>> find a solution to that together and decide if we can squeeze this one in
>> for OpenNebula 4.0. Let me explain you the main problem I see.
>>
>> So, the main concern here is that in the shared_lvm TM drivers, you're
>> operating directly on the frontend, and I think that will pose a problem if
>> you want to have multiple LVM based datastores. I don't think it's a
>> correct approach to force the OpenNebula admins to use the OpenNebula
>> frontend as their LVM primary node.
>>
>> Yes, that's why I wrote this: "Or in the case of the one driver, the HOST
> configured in the datastore config should execute this commands, but not
> the host, running the VM." This is much more elegant.
>
>
>> If you take a look at the DS/LVM drivers in the 'master' branch, you'll
>> see that we extract the LVM primary node's hostname via the 'HOST'
>> attribute of the datastore template [1]
>> The problem is, that we don't have that information in the TM drivers. A
>> solution would be to execute "onedatastore <id>" and extract the
>> datatostore's LVM primary node for each operation: cp, ln, mvds, etc...
>>
>>
>
>
>> One we have we have the name of the lvm primary node, we could follow
>> your approach: operate (clone, create, remove, etc...) in that node and
>> refresh it the nodes via lvscan and lvchange...
>>
>> any thoughts?
>>
>> [1]
>> https://github.com/OpenNebula/one/blob/master/src/datastore_mad/remotes/lvm/clone#L56
>>
>> cheers,
>> Jaime
>>
>>
>> On Tue, Mar 12, 2013 at 11:41 AM, Marlok Tamás <tmarlok at sztaki.hu> wrote:
>>
>>> Hi Jaime,
>>>
>>> I examined the new lvm driver and compared it with shared_lvm.
>>> I think, the only difference between them, is that in shared_lvm all of
>>> the lvm commands are executed on the frontend (as we described in here:
>>> http://wiki.opennebula.org/shared_lvm).
>>> I would like to suggest, that you should consider to adapt this
>>> behaviour in the new lvm driver.
>>> (Or in the case of the one driver, the HOST configured in the datastore
>>> config should execute this commands, but not the host, running the VM.)
>>>
>>> I can't see any drawback of this approach, but in this way, CLVM
>>> wouldn't be necessary (refer the wiki article).
>>>
>>> We couldn't use CLVM for various reasons, but it would be much easier
>>> for us (I think not just for us) if we could use the LVM driver already
>>> implemented in OpenNebula, instead of shared_lvm.
>>>
>>> I see, that in the datastore driver scripts this is the current
>>> behaviour. So only the tm scripts should be modified.
>>>
>>> If you can agree with this, but don't have the time for implementing,
>>> just let me know, I can create a patch for you. Or if I am wrong let me
>>> know that too :).
>>>
>>> Cheers,
>>> Tamas
>>>
>>>
>>> On Thu, Feb 21, 2013 at 6:52 PM, Jaime Melis <jmelis at opennebula.org>wrote:
>>>
>>>> Oops, you're right.
>>>>
>>>> Ok, so, can you test the upcoming LVM drivers for OpenNebula 4.0? It
>>>> replaces snapshotting with cloning...
>>>>
>>>> just replace /var/lib/one/remotes/tm/lvm
>>>> with the contents of:
>>>> https://github.com/OpenNebula/one/tree/master/src/tm_mad/lvm
>>>>
>>>> and do "onehost sync" afterwards?
>>>>
>>>>
>>>> On Thu, Feb 21, 2013 at 6:41 PM, Tobias Honacker
>>>> <t.honacker at googlemail.com>wrote:
>>>>
>>>> > Hi Jaime,
>>>> >
>>>> > yes you are right. I posted the error log file with TM_MAD="lvm",
>>>> too. I
>>>> > tried both TM_MAD=shared and lvm.
>>>> > I will try the links Mihály Héder already posted. But maybe you have
>>>> got
>>>> > any other ideas?
>>>> >
>>>> >
>>>> > Best regards,
>>>> > Tobias
>>>> >
>>>> >
>>>> > Am 21.02.2013 um 18:37 schrieb Jaime Melis:
>>>> >
>>>> > Actually, it's "onedatastore update 100", not "onetemplate"... sorry
>>>> >
>>>> >
>>>> > On Thu, Feb 21, 2013 at 6:22 PM, Jaime Melis <jmelis at opennebula.org
>>>> >wrote:
>>>> >
>>>> >> Hi Tobias,
>>>> >>
>>>> >> your datastore template has the wrong TM_MAD. It should be
>>>> TM_MAD="lvm"
>>>> >> instead of TM_MAD="shared".
>>>> >>
>>>> >> You can fix it by doing "onetemplate update 100" and editing it
>>>> in-place
>>>>
>>>
>>>
>>
>>
>> --
>> Jaime Melis
>> Project Engineer
>> OpenNebula - The Open Source Toolkit for Cloud Computing
>> www.OpenNebula.org | jmelis at opennebula.org
>>
>
>
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