OpenNebula

+1

Maybe using readlink -e since the file must exists is better.

The proposed SYMLINK image type should be able to link to other datastores, so we can setup datastores as the following:

• keep versioned images in a non public datastore, only the “image masters” can do things here
• create SYMLINK images in a “for users” datastores, referencing images in the non public one
  • users can use them, theses images are referenced in templates
  • “image masters” can manage them, mostly change the SYMLINK target

I think the SYMLINK type could apply to more than qcow2 images, I think about installation medias like debian-netinstall-amd64.iso -> debian-7.6.0-amd64-netinst.iso.

Regards.

With opennebula 4.0 and newer we can rename images in datastores so we don't need anymore use symlinks.
Our updated workflow is
1) upload newer version of image as "a_new"
2) rename "a" as "a_old" (or "a_[date]", or "a_[version]")
3) rename "a_new" as "a"
4) remove "a_old" as soon as there no more VM using it

Probably better would be feature to have a thin copy (in clone operation) of qcow2 image (as snapshot),
but that would introduce dependencies between images.

Maybe this one can be close as “will not fix” ?

Regards.