Hardware: In StarWind HCA deployments the encryption data service capabilities can be offloaded to hardware-based SED offerings available in server- and storage solutions.
Software: Microsoft Bitlocker provides software encryption on standalone and cluster based NTFS or ReFS(v2) volumes. Cluster volumes (CSV) encryption support was added in Windows 2012 Server.
Microsoft BitLocker uses the Advanced Encryption Standard (AES) encryption algorithm with either 128-bit or 256-bit keys. It is generally recommended to use 256-bit keys because of their superior strength.
For pure Windows Server StarWind HCA deployments, Bitlocker can be used to encrypt the local storage, encrypt Cluster Shared Volumes created on StarWind HA devices where VMs are located or encrypt VMs with Trusted Platform Module.
As for ESXi hosts, Bitlocker can be used to encrypt the Windows Server VMs storage (only non-bootable partitions). However, this does not provide full security. Alternatively, vSphere Virtual Machine Encryption can be used.