Losing data with persistent hard disks/images

Community Support
1

Hello all,

I have a couple of questions regarding persistence in OpenNebula. Maybe I have understood it all wrong, I don’t know: So in order to launch a VM I first upload the desired image to my OpeNebula server and check the “This image is persistent” tick-box upon doing so. I create a template afterwards, I specify all the details and select the image I want to use. Finally, I launch the VM by selecting the template and wait for it to initiate.

The thing is that, even if it says all over the place that the image that I chose is persistent, whenever I “Terminate” the VM and relaunch it back, I lose all the data/changes/etc… that were there while it was up. When I click on “Terminate” I get a warning stating that whichever hard drive that is non-persistent will lose all changes, but my hard drives/images are all persistent.

So what’s going on here? Am I missing a step in the process? Is this the normal way OpenNebula should behave?

Thanks in advance and best regards,

2

hi, your assumption about persistance is correct, all changes should be there still if an image is used with persistance=YES.

When your VM’s are running, and you check your images in the datastore, they should show up as USED_PERS, and not: USED - what does it show on your running-VM-images ?

Also, what storage subsystem are you using; ceph / local disk / NFS ?

3

Hi VURoland,

Thanks for answering, so then if my assumptions are correct my instance must be misbehaving right?

To your questions: In the datastore I see USED_PERS in my running images. I’m using a local disk storage system.

I’ve also tried to “Use the image as persistent” and to " Instantiate as persistent " both for one VM, but besides cloning the base image and the template, everything works in the same way: Once I terminate the VM I lose all changes/data… (I relaunch a VM with the cloned image)