SELECTIVE COMPRESSION IN DATA STORAGE SYSTEMS

• US 20160371190A1
• Filed: 09/30/2015
• Published: 12/22/2016
• Est. Priority Date: 12/23/2014
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: EMC Corporation (Dell Technologies Inc.)
• Inventors: Romanovskiy, Alexey Valentinovich
• Granted Patent: US 9,965,394 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 12/0868 Data transfer between cache memory and other subsystems, e.g. storage devices or host systems
• CPC Class Codes: G06F 12/0871 Allocation or management of cache space
• CPC Class Codes: G06F 12/122 of the least frequently used [LFU] type, e.g. with individual count value
• CPC Class Codes: G06F 2212/1044 Space efficiency improvement
• CPC Class Codes: G06F 2212/154 Networked environment
• CPC Class Codes: G06F 2212/3042 being part of a memory device, e.g. cache DRAM
• CPC Class Codes: G06F 2212/305 being part of a memory device, e.g. cache DRAM
• CPC Class Codes: G06F 2212/313 In storage device
• CPC Class Codes: G06F 2212/401 Compressed data
• CPC Class Codes: G06F 2212/7205 Cleaning, compaction, garbage collection, erase control
• CPC Class Codes: G06F 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/064 Management of blocks
• CPC Class Codes: G06F 3/0644 Management of space entities, e.g. partitions, extents, pools
• CPC Class Codes: G06F 3/0659 Command handling arrangements, e.g. command buffers, queues, command scheduling
• CPC Class Codes: G06F 3/0661 Format or protocol conversion arrangements
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: G06F 3/0673 Single storage device

Abstract

A method for selectively compressing data in a data storage system is provided. Data storage system cache memory is arranged into multiple input/output (IO) cache macroblocks, wherein a first set of IO cache macroblocks are configured as compressed IO cache macroblocks storing a plurality of variable sized compressed IO data blocks, and a second set of IO cache macroblocks are configured as non-compressed IO cache macroblocks storing a plurality of fixed sized non-compressed IO data blocks. An IO activity level of IO data blocks stored in IO cache macroblocks is determined. Multiple macroblock groups are created which correspond to a particular IO activity level. IO data blocks are arranged into macroblocks belonging to a macroblock category according to data block IO activity level. Each macroblock group is compressed, wherein compressing includes selecting a compression algorithm based on the macroblock category. The macroblocks are written to corresponding macroblocks in persistent storage.

Claims

1. A method for selectively compressing data in a data storage system, the method comprising:

arranging data storage system cache memory into multiple input/output (IO) cache macroblocks, wherein a first set of IO cache macroblocks are configured as compressed IO cache macroblocks, each compressed IO cache macroblock storing a plurality of variable sized compressed IO data blocks, and a second set of IO cache macroblocks are configured as non-compressed IO cache macroblocks, each non-compressed IO cache macroblock storing a plurality of fixed sized non-compressed IO data blocks;

determining IO activity level of IO data blocks stored in IO cache macroblocks;

creating a plurality of macroblock groups, wherein the macroblock groups correspond to a particular IO activity level;

arranging IO data blocks into a macroblock belonging to a macroblock category according to data block IO activity level;

compressing each macroblock group, wherein compressing includes selecting a compression algorithm based on the macroblock category; and

writing the macroblocks to corresponding macroblocks in persistent storage.

2. The method of claim 1, wherein creating the macroblock groups includes creating macroblocks that correspond to data block content.

3. The method of claim 2, wherein the data block content is text associated with a text file.

4. The method of claim 1, wherein arranging IO data blocks includes arranging IO data blocks into a macroblock belonging to a macroblock category according to data block content.