snapshot raw image by converting it to a qcow2 image

[Nowaker]

Original subject: "snapshot" raw image

Only qcow format supports snapshots. For raw images we could just cp --sparse image.raw image-snapshot-YYYYMMDD.raw. However, this should be allowed only when the machine is off (qcow can snapshot at any time). Because "snapshots" of raw images may be large, a new permission "snapshot_raw_create" should be introduced.

[CyrilPeponnet]

As I can tell snapshoting a raw image is possible through libvirt :

The original disk image can be either in RAW format or QCOW2 format. When a snapshot is taken, ‘the difference’ will be stored in a different QCOW2 file

http://kashyapc.com/2012/09/14/externaland-live-snapshots-with-libvirt/

[Nowaker]

Raw image is a blob of data exposed directly in VM as block device, it can't snapshot. qemu-img is able to import data from raw image into qcow2 image, and save it as snapshot - that's what you provided. This could be an additional feature, but I don't think many people would use it. If they chose raw format in the beginning, they have a reason for it.

Anyway, it would be good to introduce separate buttons for each feature, and activate some depending on the format of currently selected disk:

• snapshot QCOW image
• backup RAW image
• convert and snapshot RAW to QCOW image

[CyrilPeponnet]

Or just changing the warning telling that the raw disk will must be converted as qcow2 for snapshot purpose.

Backuping a RAW image can be done by cloning the VM (I'm not sure what you mean by backuping).

We are trying to fit in the libvirt API so it's could become a big mess if we start to implements different behavior for each cases. Snapshoting is not only a matter of disk, it will snapshot also the memory (with options) and create a snapshot definition file.

My thought is to use qcow or convert the disk to it if the user want to deal with snapshots.

[Nowaker]

We are trying to fit in the libvirt API so it's could become a big mess if we start to implements different behavior for each cases.

Indeed. Just changed the issue title to reflect this.

[CyrilPeponnet]

What can I do with this one ? The error message is raised by libvirt so I can hardly change it. On the other hand if libvirt start to implement let say, an improved snapshoting behavior, it will be compatible as is.

[Nowaker]

What does the error say?

[CyrilPeponnet]

unsupported configuration: internal snapshot for disk hda unsupported for storage type raw archipel:virtualmachine:snapshotingtake