Selective compression in data storage systems

Patent metadata

Field	Value
Publication number	US-9965394-B2
Application number	US-201515122302-A
Country	US
Kind code	B2
Filing date	Sep 30, 2015
Priority date	Dec 23, 2014
Publication date	May 8, 2018
Grant date	May 8, 2018

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.

First claim

What is claimed is:

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, wherein the first and second set of IO cache macroblocks are stored in memory as contiguous segments having a fixed size;
determining IO activity level of IO data blocks stored in IO cache macroblocks;
creating a plurality of macroblock groups, wherein each macroblock group corresponds to a particular IO activity range;
arranging IO data blocks into of the macroblock groups according to the IO activity range that corresponds to the data block IO activity level;
compressing each macroblock group, wherein compressing includes selecting a software compression algorithm based on the IO activity range of the macroblock group; 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.

Assignees

• Emc Corp
• Emc Ip Holding Co Llc

Inventors

• Romanovskiy Alexey Valentinovich

Classifications

• G06F3/0644

  Management of space entities, e.g. partitions, extents, pools · CPC title

• G06F3/067

  Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS] · CPC title

• G06F3/0673

  Single storage device · CPC title

• G06F3/0608 Primary

  Saving storage space on storage systems · CPC title

• G06F3/064

  Management of blocks · CPC title