Persistent storage device with NVRAM for staging writes

摘要

A persistent storage device includes both persistent storage, which includes a set of persistent storage blocks, and NVRAM, and in particular a set of NVRAM blocks. The persistent storage device also typically includes a storage controller. The persistent storage device, in addition to responding to commands to write data directly to and to read data directly from persistent storage blocks is also configured to write data to specified NVRAM blocks (e.g., specified by a host NVRAM write command) and to transfer data from a specified NVRAM block to a specified persistent storage block. As a result, multiple writes to a particular persistent storage block can be replaced with multiple writes to an NVRAM block and a subsequent single write to the particular persistent storage block. This reduces the number of writes to persistent storage and also reduces the number of corresponding block erase operations.

主权项

1. A persistent storage device, comprising:
persistent storage, comprising a set of persistent storage blocks; NVRAM, comprising a type of nonvolatile storage distinct from the persistent storage and comprising a set of NVRAM blocks; a storage controller configured to receive commands from an external host device in accordance with one or more applications executed by the external host device, and further configured to:
in response to a host NVRAM write command received from the external host device, store data to an NVRAM block specified by the host NVRAM write command;in response to a host NVRAM read command received from the external host device, retrieve data from an NVRAM block specified by the host NVRAM read command; andin response to a transfer command received from the external host device, transfer data in an NVRAM block specified by the transfer command to a corresponding persistent storage block, wherein the data was previously written to the specified NVRAM block.