What VMDK version does Proxmox use?

[Raident]

When I open a Proxmox VMDK file in VMware Workstation 10, I get asked if I want to upgrade the VMDK to the latest version.

 

[moarph]

According to this, it should be Version 6. http://en.wikibooks.org/wiki/QEMU/Images If you upgrade to Version 10 you should be unable to open it with Proxmox anymore.