Update: The provided link is no longer working, so the updated link is: http://www8.hp.com/us/en/products/data-storage/free-sovsa.html. Kudos to Ventzislav.
Since April 2015 HP is offering a zero cost 1 TB version of the HP StoreOnce VSA. The software-defined backup solution provides you secure backup for your applications with reduced storage costs, power consumption, and rackspace requirements. This free version is ideal to protect small amounts of data, especially in very small remote offices / branch offices (or at home, as I do, yeah…). With the included low-bandwidth replication you can easily replicate the backups from your small offices to the StoreOnce system in your central site without re-hydrating the data. Assuming a typical 20:1 deduplication ratio you can store a lot of backups onto the free 1 TB StoreOnce VSA. And if 1 TB is not enough, the StoreOnce VSA is available as 4 TB, 10 TB and 50 TB version. In larger environments, the HP StoreOnce appliances might be the better choice. Of course HP StoreOnce best works with HP Data Protector, but can be used with Symantec Backup Exec and NetBackup (now again Veritas), CommVault, Veeam and other ISV’s too.
Link to unlock StoreOnce: http://www.hp.com/go/freebackup
What are you waiting for? Unlock your free 1 TB HP StoreOnce VSA today and experience the great value with the StoreOnce technology!