What is BitLocker and why should I use this feature on my Windows Server 2012 platforms? Is there a server performance penalty if I deploy BitLocker?
BitLocker is an encryption tool available in all versions of Windows Server 2012 as well as in Windows 8 Pro and Enterprise. BitLocker encryption can be installed on a server using the Server Manager utility. It encrypts all user and system files on a hard drive, which includes common security vulnerabilities like swap and hibernation files. Once deployed, the system requires proper authentication -- such as an encryption key -- to access encrypted data and to boot Windows Server 2012.
Servers that use a trusted platform module can tie BitLocker authentication to the unique server hardware. This ensures the drive is decrypted and accessed by a specific server that is unaltered against an existing hardware "fingerprint."
BitLocker encryption supports several methods for access, but typical servers are configured to unlock local drives automatically when the system boots and comes online. End users with Windows 8 can take advantage of alternative access methods like passwords, smart cards or Active Directory keys for drive authentication.
Encryption is a mathematically intensive process that requires processing overhead when encrypting and decrypting data. However, the actual performance penalty for encryption is quite low for most current-generation servers. Microsoft documentation notes that BitLocker encryption imposes less than a 10% performance penalty.
The actual amount of overhead depends on the server hardware, the storage subsystem, the presence of virtualization and the actual amount of data each workload produces. The best way to determine the impact of BitLocker encryption is to benchmark server performance before and after deployment in a controlled environment before introducing it to production.
This was first published in April 2013