US Patent 8949180 Replicating key-value pairs in a continuous data protection system

In one aspect, a method to replicate a key-value pair includes intercepting a command to update a key-value pair in a key-value pair database, the key-value database comprising metadata of a virtual volume, sending an updated key-value pair to a data protection appliance, receiving an acknowledgement that the data protection appliance received the updated key-value pair and updating the key-value pair in the key-value database after the acknowledgement is received.