Explain how and in which data center environment Veritas Vray edition can be useful?

The Backup Exec V-Ray Edition is designed exclusively for virtual environments. Ultimately, with the Backup Exec V-Ray Edition you get all the software you need to completely protect your virtual environment

The Backup Exec V-Ray Edition is licensed per socket and includes the following software components:

• Backup Exec Media Server (x1 license)
• Backup Exec Agent for VMware and Hyper-V (unlimited licenses)
• Agent for Applications and Databases (unlimited licenses)
  • Exchange
  • SQL
  • SharePoint
  • Active Directory
  • Oracle
  • Lotus Domino
  • Enterprise Vault
• Backup Exec Deduplication Option (x1 license)

Talking about your query, when you have majority of virtualized infrastructure (VMware or Hyper-V) and majority of Windows OS virtual machines, you should think about V-Ray edition. It benefit of this edition is as listed below.

Protection for All Virtual Machines

Application Data Granular Recovery in both virtual and physical environments

The typical scenario going for V-Ray Edition is:

• Virtual and physical environment -- 6 x V-Ray Edition

• 3 ESXi hosts, dual processors -- 3 x Agent for Windows

• 25 virtual machines -- 1 x Agent for Linux

• 3 Windows file servers (physical) -- 1 x Agent for Applications and Databases

   1 Linux server (physical) -- 

   1 SQL server (physical)

• 1 tape autoloader with 1 drives

• Needs deduplication & central management  -- 1 x Enterprise Server Option