Sometime you may have to open OVA files, which are actually just zip of OVF files.
You can extract or convert OVA to OVF file in three ways as mentioned below
If you have access to Linux or Unix box you can use tar command to extract the file.
tar -xvf cloudvedas-OpenStackHOL.ova
In Windows you can use a tool like like 7-Zip or winrar to extract the file.
Once you have downloaded and installed the tool go to the command prompt and change the directory to where you have installed the ovf tool. You should see an exe called “ovftool.exe”.
Execute the command:-
ovftool.exe "E:\Software\Openstack\cloudvedas-OpenStackHOL.ova" "E:\Software\Openstack\cloudvedas-OpenStackHOL.ovf"