Last time I implemented encryption at rest (when I worked for a small cloud provider), it was as easy as adding an option when creating the disk. The option tr

Last time I implemented encryption at rest (when I worked for a small cloud provider), it was as easy as adding an option when creating the disk. The option triggered the implementation of a dm-crypt layer between the physical device and the upper storage layers. Crypto keys were stored in the storage system. Once revoked, the whole server was rendered useless (from a data thief point of view). We benchmarked the stuff a bit. Indeed, there was a loss. While dm-crypt uses AES (with hardware acceleration) and since we had multi-hundreds of thousands IOPS per device, we did not care.