Ioncube seem to bind their software to hardware and network interfaces. If you have a valid license and you are going to upgrade your hardware or OS there is a safe way to retain the license.
To get basic help about what you are doing, read the license section in:
Redeem license cancel request and send as a letter attachment to ioncube support:
This will revoke an existing encoder license. After running this command a file revoke_file-n.txt will be created in the encoder installation directory. Send the revoke file to licenses AT ioncube.com for your license to be revoked ready for allocation to a different machine.
You can now do what you planned with your hardware and software. When done:
Generate a licreq.txt license request in a usual way and send to licenses AT ioncube.com (does not work during the week-end!). Use as usual.