Le 11/10/2013 11:46, Dafna Ron a écrit :

yeah, data domain cannot be removed while having objects on it.

what you can do is this:

1. if you want to be able to move vms from one setup to another you need to use the Export domain. You can back up your vms on that and attach and detach it from different setups (but it can only be attached on one Data Center at a time to avoid corruption from two different users exporting the same vm or writing to the same spot).

Yes, I already succeeded in doing that, and this is convenient. But the goal of this discussion is to deal with a disaster. When all what's left is a SAN, how can I import these data into a new oVirt? I'm open minded, and any solution will be welcomed.

2. I am not sure that you can run a vm created in 3.3 DC/cluster level to 3.1, or at lease run it with no issues at all because of version changes made. but worth to try and report any issues :)

Dafna

On 10/11/2013 10:36 AM, Nicolas Ecarnot wrote:

...

Hi,

At present, I have a 3.1 oVirt setup and a new 3.3 other oVirt setup. Those two setups have no relations, except they are plugged on the same iSCSI SAN.

I was trying to to the following test : - on ovirt3.1, create a new storage domain - put it a VM disk - shutdown this VM - desactivate the storage domain - detach it

- on the ovirt3.3, attach this storage domain as an additionnal one (obviously, I already have a master domain) - activate it - start the VM

But on the first part of this plan, I can't even detach it because "Cannot detach Storage Domain while VMs/Templates reside on it. -Please remove all objects and try again."

Well, OK.

In fact, let's forgot the speach above and just read this : I'm trying to understand what I can do with my oVirt LUNs when I get a complete serious crash (datacenter on fire) and I just have the SAN. I was hoping I could import the storage domains into another oVirt setup. Maybe I should store data another way?

I'm sure you know the best practices - the oVirt way.

-- Nicolas Ecarnot

On 10/11/2013 04:37 PM, Nicolas Ecarnot wrote:

Le 11/10/2013 13:55, Itamar Heim a écrit :

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also review this thread http://lists.ovirt.org/pipermail/users/2013-October/016725.html

Thank you Itamar.

In this helpful thread, I read :

...

for 3.3, there a few options (the first one is the cleanest) 1. "save the export part" - stop using the domain in 3.1 - change its meta data to that of an export domain - import it as an existing export domain to 3.3 - import the VMs

I don't even know how to do the first line "stop using the domain" : - I have stopped the VM that has a disk on this domain - I have put it into maintenance mode - I can't detach it from the data center, as said before, because it sees there are still some VM on it.

All this is in a iSCSI context.

When I pass this first step, I'll have to guess how to "change the meta data"...

sorry, that's not trivial for an iSCSI. more for NFS (which can behave as an export domain as well). for iSCSI, export/import is the most trivial approach (until we add "import data domain")