Cached volumes at storage gateways

摘要

Methods and apparatus for supporting cached volumes at storage gateways are disclosed. A storage gateway appliance is configured to cache at least a portion of a storage object of a remote storage service at local storage devices. In response to a client's write request, directed to at least a portion of a data chunk of the storage object, the appliance stores a data modification indicated in the write request at a storage device, and asynchronously uploads the modification to the storage service. In response to a client's read request, directed to a different portion of the data chunk, the appliance downloads the requested data from the storage service to the storage device, and provides the requested data to the client.

主权项

1. A method, comprising:
designating a first space on a storage device of a storage appliance to (a) cache at least a portion of one or more data chunks of a storage object of a remote storage service, wherein each chunk of the one or more data chunks comprises one or more data blocks and (b) store inline metadata for the data blocks of the one or more data chunks, wherein the inline metadata for a particular data block comprises a plurality of metadata elements; designating a second space on the storage device to store contiguous metadata for the one more data chunks of the storage object, wherein at least a portion of the contiguous metadata is based at least in part on a portion of inline metadata stored in the first space; updating a particular portion of the contiguous metadata based at least in part on a modification of at least one element of inline metadata, wherein said updating the particular portion of the contiguous metadata is performed asynchronously with respect to the modification of the at least one element of inline metadata; and after a controlled shutdown and restart of the storage appliance, determining a state of a particular data chunk of the one or more data chunks using at least the particular portion of the contiguous metadata, and enabling client access to the particular data chunk dependent upon a result of said determining.