[one-users] Image Manager and Transfer Manager drivers

[Ruben S. Montero]

>I can read that the mkimage and mkswap commands
> respectively create empty and swap images in <destination>. I assume
> <destination> will be a worker, so it will be a path of the form
> <VM_DIR>/<VM_ID>/images/<filename>. Is that right?

Yes

>And in which situations
> will these commands actually be used?

When you specify them in a DISK stanza with TYPE equal to SWAP or FS.

>Is tm_clone not used to copy empty
> images from the repository to the VM_DIR?

Yes. There are two "low-level" attributes that control that CLONE and
SAVE. These attributes are translated from the image attributes
(persistent or not). If you defined a DISK with CLONE = yes CLONE will
be used if not MV. Note that depending on the driver MV may mean CLONE
(for example with ssh there is no means of MV the images so CLONE is
basically MV)

> You say that tm_mv is used to move the images from the host to the VM_DIR at
> the front-end. What is this needed for (i.e. in which situation is
> executed)?

1.- Stop operation will MV back images and checkpoint for later restore them
2.- Any DISK with SAVE = YES (A persistent image would be an example)

>Is this command needed if the VM_DIR is shared between the
> front-end and the workers? (I would say no)

Take a look to the shared FS driver there are situations that deal
with differen the mount points...

Cheers

Ruben
> Thanks again.
> Cheers,
> Humberto
>
>
>
>
> On Mon, Nov 14, 2011 at 10:23 AM, Ruben S. Montero
> <rsmontero at opennebula.org> wrote:
>>
>> Hi,
>>
>> Basically you have to storage areas:
>>
>> * The image repository, where your base images are kept. Any operation
>> to copy or move an image from there are through the Image driver. This
>> is for: 1) Resitering a new image (CP) 2) Creating an empty image
>> (MKFS) 3) Copy back a persistent image or a saved_as one (MV)  and 4)
>> delete an image (RM)
>>
>> * The storage at the hosts and the VM_DIR (can be local or in a shared
>> FS). Transfer operations to/from that directories are handle with the
>> TM. TM move is then used to move the images from the host to the
>> VM_DIR at the front-end.
>>
>> Cheers
>>
>> Ruben
>>
>> On Wed, Nov 9, 2011 at 3:08 PM, Humberto N. Castejon Martinez
>> <humcasma at gmail.com> wrote:
>> > Hi,
>> >
>> > I have two questions regarding some of the commands in these two sets of
>> > drivers.
>> > When is the IM's mkfs command used and when the TM's mkimage command ?
>> > When (for what) is the   IM's mv command used? (I understand the TM's mv
>> > command is used to move the image used by a running VM back to the
>> > repository, right?)
>> > Thanks.
>> > Cheers,
>> > Humberto
>> > _______________________________________________
>> > Users mailing list
>> > Users at lists.opennebula.org
>> > http://lists.opennebula.org/listinfo.cgi/users-opennebula.org
>> >
>> >
>>
>> --
>> Ruben S. Montero, PhD
>> Project co-Lead and Chief Architect
>> OpenNebula - The Open Source Toolkit for Data Center Virtualization
>> www.OpenNebula.org | rsmontero at opennebula.org | @OpenNebula
>
>



-- 
Ruben S. Montero, PhD
Project co-Lead and Chief Architect
OpenNebula - The Open Source Toolkit for Data Center Virtualization
www.OpenNebula.org | rsmontero at opennebula.org | @OpenNebula