# Question about non-persistent disk
**URL:** https://forum.opennebula.io/t/question-about-non-persistent-disk/2971
**Category:** Product Support
**Created:** [September 22, 2016, 3:18pm UTC](https://forum.opennebula.io/t/question-about-non-persistent-disk/2971 "2016-09-22T15:18:36Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@vynt-kenshiro](https://forum.opennebula.io/u/vynt-kenshiro)
#### Post date: [September 22, 2016, 3:18pm UTC](https://forum.opennebula.io/t/question-about-non-persistent-disk/2971/1 "2016-09-22T15:18:36Z")
Hello,
From [http://docs.opennebula.org/5.2/operation/vm\_management/vm\_templates.html](http://docs.opennebula.org/5.2/operation/vm_management/vm_templates.html), a vm can have three types of disk:
- Use a persistent Image: changes to the disk image will persist after the VM is terminated.
- Use a non-persistent Image: a copy of the source Image is used, changes made to the VM disk will be lost.
- Volatile: disks are created on the fly on the target host. After the VM is terminated the disk is disposed.
As I understand the VM use non-persistent disk/image only lost data when VM is terminated. Is that correct? I am very appreciated for anyone help me explain more about non-persistent image/disk.
Thanks,
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### Author:  [@cro](https://forum.opennebula.io/u/cro)
#### Post date: [September 22, 2016, 3:59pm UTC](https://forum.opennebula.io/t/question-about-non-persistent-disk/2971/2 "2016-09-22T15:59:23Z")
I had trouble with this concept when I started using OpenNebula also. It made more sense to me when I started thinking about it in terms of what the public cloud providers do. If you spin up a machine at Linode for example, the data on your disks will only persist until you destroy that machine. You can power-off and reboot the machine as much as you like, but the disk will stick around until you delete the VM.
ONE works the same way–most of our usage (99+%) is with non-persistent disks. ONE has some extra features that most cloud providers don’t though, you can ‘undeploy’ a VM and it will shut down and be essentially removed from the hypervisor until you ‘deploy’ it again, but the disk won’t be destroyed even though it’s non-persistent.
If you need to save the data that’s on a non-persistent disk you can do a ‘save as’ from SunStone or use the CLI to turn an existing non-persistent disk into a persistent one.
Does that help?
–cro
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### Author:  [@vynt-kenshiro](https://forum.opennebula.io/u/vynt-kenshiro)
#### Post date: [September 22, 2016, 5:38pm UTC](https://forum.opennebula.io/t/question-about-non-persistent-disk/2971/3 "2016-09-22T17:38:56Z")
Hi cro,
Thank you for your very informative and valuable reply to my question. It helped me to understand better some Open Nebula concepts. Once again, thank you for your help.