Storage subsystem including logic for copy-out and write

摘要

A storage server receives a write request from a client system including new data and a location to store the new data. The storage server transmits a copy instruction to a storage subsystem to relocate old data at the location and transmits a write instruction to the storage subsystem to overwrite the old data with the new data. The storage subsystem includes fast stable storage in which the copy instruction and the write instruction are stored. After receiving each instruction, the storage subsystem sends an acknowledgement to the storage server. When both instructions have been acknowledged, the storage server sends an acknowledgement to the client system. The storage subsystem performs the instructions asynchronously from the client system's write request.

主权项

1. A method performed by a storage server, the method comprising:
receiving a write request from a client system, the write request comprising data to be written and a location in a storage space; transmitting a copy instruction to a storage subsystem, the copy instruction indicating to copy existing data at the location in the storage space to a new location; receiving an acknowledgement of the copy instruction from the storage subsystem; transmitting, in response to the acknowledgement of the copy instruction, a write instruction to the storage subsystem, the write instruction indicating to write the data to be written to the location in the storage space; receiving an acknowledgement of the write instruction from the storage subsystem; and transmitting, in response to the acknowledgement of the write instruction, an acknowledgement of the write request to the client system.