Symantec Backup Exec with ESXi Free Version

Hi All,

I using ESXi 5.1 Free version one host and 3 windows server 2008 R2 guest OS.

I need to backup and plan to purchase Symantec Backup Exec 2012 on next month but vendor said "all backup software not support ESXi Free" because service API disable so, I have to purchase vSphere Essentials.

Is it factual information? If yes, Can suggest me for other solution?

Thanks

Preeda S.