On Wed, Jun 14, 2017 at 9:23 AM, Idan Shaby <ish...@redhat.com> wrote:

> Direct luns are disks that are not managed by oVirt. Ovirt communicates
> directly with the lun itself, without any other layer in between (like lvm
> in image disks).
> The advantage of the direct lun is that it should have better performance
> since there's no overhead of another layer in the middle.
> The disadvantage is that you can't take a snapshot of it (when attached to
> a vm, of course), can't make it a part of a template, export it, and in
> general - you don't manage it.
>

You can, of course, create a snapshot from the storage-side.
Y.


>
> Regards,
> Idan
>
> On Mon, Jun 12, 2017 at 10:10 PM, Stefano Bovina <bov...@gmail.com> wrote:
>
>> Thank you very much.
>> What about "direct lun" usage and database example?
>>
>>
>> 2017-06-08 16:40 GMT+02:00 Elad Ben Aharon <ebena...@redhat.com>:
>>
>>> Hi,
>>> Answer inline
>>>
>>> On Thu, Jun 8, 2017 at 1:07 PM, Stefano Bovina <bov...@gmail.com> wrote:
>>>
>>>> Hi,
>>>> does a storage best practise document for oVirt exist?
>>>>
>>>>
>>>> Some examples:
>>>>
>>>> oVirt allows to extend an existing storage domain: Is it better to keep
>>>> a 1:1 relation between LUN and oVirt storage domain?
>>>>
>>> What do you mean by 1:1 relation? Between storage domain and the number
>>> of LUNs the domain reside on?
>>>
>>>> If not, is it better to avoid adding LUNs to an already existing
>>>> storage domain?
>>>>
>>> No problems with storage domain extension.
>>>
>>>>
>>>> Following the previous questions:
>>>>
>>>> Is it better to have 1 Big oVirt storage domain or many small oVirt
>>>> storage domains?
>>>>
>>> Depends on your needs, be aware to the following:
>>> - Each domain has its own metadata which allocates ~5GB of the domain
>>> size.
>>> - Each domain is being constatntly monitored by the system, so large
>>> number of domain can decrease the system performance.
>>> There are also downsides with having big domains, like less flexability
>>>
>>>
>>>> There is a max num VM/disks for storage domain?
>>>>
>>>>
>>>> In which case is it better to use "direct attached lun" with respect to
>>>> an image on an oVirt storage domain?
>>>>
>>>
>>>>
>>>
>>>> Example:
>>>>
>>>> Simple web server:   ----> image
>>>> Large database (simple example):
>>>>    - root,swap etc: 30GB  ----> image?
>>>>    - data disk: 500GB    -----> (direct or image?)
>>>>
>>>> Regards,
>>>>
>>>> Stefano
>>>>
>>>> _______________________________________________
>>>> Users mailing list
>>>> Users@ovirt.org
>>>> http://lists.ovirt.org/mailman/listinfo/users
>>>>
>>>>
>>>
>>
>> _______________________________________________
>> Users mailing list
>> Users@ovirt.org
>> http://lists.ovirt.org/mailman/listinfo/users
>>
>>
>
> _______________________________________________
> Users mailing list
> Users@ovirt.org
> http://lists.ovirt.org/mailman/listinfo/users
>
>
_______________________________________________
Users mailing list
Users@ovirt.org
http://lists.ovirt.org/mailman/listinfo/users

Reply via email to