Resizable cache system and method

Patent metadata

Field	Value
Publication number	US-10817429-B1
Application number	US-201514871865-A
Country	US
Kind code	B1
Filing date	Sep 30, 2015
Priority date	Sep 30, 2015
Publication date	Oct 27, 2020
Grant date	Oct 27, 2020

Abstract

A method, computer program product, and computing system for freeing up cache space includes identifying a portion of cache space for removal from a cache system, thus defining a cache portion to be removed, and ceasing to promote the cache portion to be removed. Data that needs to be relocated within the cache portion to be removed is identified, thus identifying flushable data. The flushable data is relocated to a backend storage system associated with the cache portion to be removed.

First claim

What is claimed is:

1. A computer-implemented method for freeing up cache space comprising:
identifying a portion of cache space for removal from a mirrored cache system of one or more solid-state disks chosen from a plurality of solid-state disks within the cache system, wherein the portion of cache spaced identified for removal is cache space in a first cache system associated with a first storage processor;
identifying a mirrored portion associated with the identified portion of cache space for removal, wherein the identified portion of cache space for removal and the mirrored portion associated with identified portion of cache space for removal define a cache portion to be removed, wherein the mirrored portion associated with the identified portion of cache space for removal is a cache space in a second cache system associated with a second storage processor;
in response to identifying the associated mirrored portion of cache space, ceasing to promote the cache portion to be removed and the associated mirrored portion as available for storing additional data to be written to a data array;
in response to ceasing to promote the cache portion to be removed and the associated mirrored portion as available for storing additional data to be written to a data array, identifying data within the cache portion to be removed that needs to be relocated in response to ceasing to promote the cache portion to be removed, thus identifying flushable data;
relocating the flushable data to a backend storage system associated with the cache portion to be removed; and
defining the cache portion to be removed as storage space available for reallocation, wherein each of the identified portion of cache space for removal and the mirrored portion associated with identified portion of cache space for removal are concurrently defined as storage space available for allocation when the flushable data is relocated to the backend storage system.

2. The computer-implemented method of claim 1 wherein the cache system is a flash-based cache system.

3. The computer-implemented method of claim 1 wherein the flushable data is dirty data.

4. A computer program product residing on a non-transitory computer readable medium having a plurality of instructions stored thereon which, when executed by a processor, cause the processor to perform operations comprising:
identifying a portion of cache space for removal from a mirrored cache system of one or more solid-state disks chosen from a plurality of solid-state disks within the cache system, wherein the portion of cache spaced identified for removal is cache space in a first cache system associated with a first storage processor;
identifying a mirrored portion associated with the identified portion of cache space for removal, wherein the identified portion of cache space for removal and the mirrored portion associated with identified portion of cache space for removal define a cache portion to be removed, wherein the mirrored portion associated with the identified portion of cache space for removal is a cache space in a second cache system associated with a second storage processor;
in response to identifying the associated mirrored portion of cache space, ceasing to promote the cache portion to be removed and the associated mirrored portion as available for storing additional data to be written to a data array;
in response to ceasing to promote the cache portion to be removed and the associated mirrored portion as available for storing additional data to be written to a data array, identifying data within the cache portion to be removed that needs to be relocated in response to ceasing to promote the cache portion to be removed, thus identifying flushable data;
relocating the flushable data to a backend storage system associated with the cache portion to be removed; and
defining the cache portion to be removed as storage space available for reallocation, wherein each of the identified portion of cache space for removal and the mirrored portion associated with identified portion of cache space for removal are concurrently defined as storage space available for allocation when the flushable data is relocated to the backend storage system.

5. The computer program product of claim 4 wherein the cache system is a flash-based cache system.

6. The computer program product of claim 4 wherein the flushable data is dirty data.

7. A computing system including a processor and memory configured to perform operations comprising:
identifying a portion of cache space for removal from a mirrored cache system of one or more solid-state disks chosen from a plurality of solid-state disks within the cache system, wherein the portion of cache spaced identified for removal is cache space in a first cache system associated with a first storage processor;
identifying a mirrored portion associated with the identified portion of cache space for removal, wherein the identified portion of cache space for removal and the mirrored portion associated with identified portion of cache space for removal define a cache portion to be removed, wherein the mirrored portion associated with the identified portion of cache space for removal is a cache space in a second cache system associated with a second storage processor;
in response to identifying the associated mirrored portion of cache space, ceasing to promote the cache portion to be removed and the associated mirrored portion as available for storing additional data to be written to a data array;
in response to ceasing to promote the cache portion to be removed and the associated mirrored portion as available for storing additional data to be written to a data array, identifying data within the cache portion to be removed that needs to be relocated in response to ceasing to promote the cache portion to be removed, thus identifying flushable data;
relocating the flushable data to a backend storage system associated with the cache portion to be removed; and
defining the cache portion to be removed as storage space available for reallocation, wherein each of the identified portion of cache space for removal and the mirrored portion associated with identified portion of cache space for removal are concurrently defined as storage space available for allocation when the flushable data is relocated to the backend storage system.

8. The computing system of claim 7 wherein the cache system is a flash-based cache system.

9. The computing system of claim 7 wherein the flushable data is dirty data.

Assignees

• Emc Corp
• Emc Ip Holding Co Llc

Inventors

• Xu Xinlei
• Li Xiongcheng
• Harvey John V
• Yang Lifeng
• Gao Jian

Classifications

• G06F2212/312

  In storage controller · CPC title

• G06F2212/286

  Mirrored cache memory · CPC title

• G06F2212/263

  Network storage, e.g. SAN or NAS · CPC title

• G06F2212/222

  Non-volatile memory · CPC title

• G06F2212/154

  Networked environment · CPC title