Storage array controller for flash-based storage devices

• US 8,850,114 B2
• Filed: 01/03/2011
• Issued: 09/30/2014
• Est. Priority Date: 09/07/2010
• Status: Expired due to Fees

• Current Assignee: Daniel L. Rosenband
• Original Assignee: Daniel L. Rosenband
• Inventors: Rosenband, Daniel L, Smith, Michael John Sebastian
• Primary Examiner(s): NGUYEN, HIEP T
• Application Number:
  US12/983,876
• Publication Number:
  US 20120059978A1
• Time in Patent Office: 1,366 Days
• US Class Current: 711/114
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 12/0253 Garbage collection, i.e. reclamation of unreferenced memory
• CPC Class Codes: G06F 2212/7205 Cleaning, compaction, garbage collection, erase control
• CPC Class Codes: G06F 3/0613 in relation to throughput
• CPC Class Codes: G06F 3/0659 Command handling arrangements, e.g. command buffers, queues, command scheduling
• CPC Class Codes: G06F 3/0688 Non-volatile semiconductor memory arrays
• CPC Class Codes: H01G 11/16 against electric overloads, e.g. including fuses

Abstract

The invention is an improved storage array controller that adds a level of indirection between host system and storage array. The storage array controller controls a storage array comprising at least one solid-state storage device. The storage array controller improvements include: garbage collection, sequentialization of writes, combining of writes, aggregation of writes, increased reliability, improved performance, and addition of resources and functions to a computer system with a storage subsystem.

Claims

1. A storage array controller operable to be coupled to a host system;

wherein the storage array controller controls a storage array;

wherein the storage array comprises a plurality of solid-state disks;

wherein the plurality of solid-state disks form a RAID array;

wherein the storage array controller creates a map to perform data manipulation across at least one of the plurality of solid-state disks;

wherein the storage array controller includes an operating system;

wherein the operating system is operable to alter the map of one or more input addresses to one or more output addresses;

wherein the storage array controller uses the map to map addresses between one or more host commands and one or more disk commands;

wherein the storage array controller is operable to perform one or more re-mapping operations between the host system and the storage array;

wherein the storage array controller is operable to use a freelist of addresses that are free to be used. wherein one or more garbage collection operations are performed by the storage array controller independently from the host system;

and wherein the storage array controller is operable to perform the map of input addresses to output addresses while performing one or more garbage collection operations.

2. The storage array controller of claim 1 wherein the input addresses and/or output addresses may be blocks and/or sectors.

3. The storage array controller of claim 1 wherein one or more of the one or more garbage collection operations are further performed by the storage array controller issuing one or more disk trim commands issued to the plurality of solid-state disks;

and wherein one or more of the one or more disk trim commands are generated independently from the host system.

4. The storage array controller of claim 1;

wherein the storage array controller is further operable to perform the map of input addresses to output addresses while performing one or more operations to reduce wear;

and wherein the operations to reduce wear include the balancing and re-balancing of data across one or more of the plurality of solid-state disks.

5. The storage array controller of claim 4 wherein the re-balancing of data includes moving one or more areas of hot data from a first solid-state disk to a second solid state disk.

6. The storage array controller of claim 1 wherein the storage array controller is further operable to perform the map of input addresses to output addresses while performing one or more operations to balance spare capacity.

7. The storage array controller of claim 6 wherein the balancing of spare capacity includes altering the map so that a first solid-state disk that has a nearly full capacity and a second solid-state disk that has unused capacity are balanced so that the first solid-state disk and the second solid-state disk have the same or nearly the same spare capacity.

8. The storage array controller of claim 1;

wherein the RAID array is a RAID5 array;

wherein the storage array controller is further operable to perform the map of input addresses to output addresses while performing one or more operations to sequentialize writes;

and wherein the storage array controller is operable to perform one or more write commands in units of the RAID5 stripe size without using a read-modify-write operation.

9. The storage array controller of claim 1;

wherein the storage array controller is operable to stream data directly to and from the host system and wherein the streaming of data bypasses one or more host system hardware layers and/or one or more host software driver layers.