Subscription licenses allow you to protect all supported operating systems and applications without any limitations. For example, with an Acronis Backup Advanced for Server subscription, you can protect any physical server (Windows or Linux), any virtual host (VMware, Hyper-V, Xen, KVM, RHEV, Oracle VM), and all applications on the server (Exchange, SQL, SharePoint and Active Directory). You also get 24/7 technical support and free upgrades to new versions.
Perpetual licenses are still available for fit specific customers' needs.
Refer to this comparison table to select the license you need.