Managing data storage

Patent metadata

Field	Value
Publication number	US-10901843-B2
Application number	US-201916432680-A
Country	US
Kind code	B2
Filing date	Jun 5, 2019
Priority date	Mar 31, 2014
Publication date	Jan 26, 2021
Grant date	Jan 26, 2021

Abstract

Disclosed herein are techniques for use in managing data storage. For example, in one embodiment, the techniques comprise determining a size of the write request. The size of the write request equating to half or more non-parity data portions in a full stripe of data but less than all non-parity data portions in the full stripe. The techniques comprise performing a process based on the size that includes reading a parity and one or more missing non-parity data portions in the full stripe, verifying the coherency of the missing non-parity data portions by comparing a checksum of the parity and a checksum of the missing non-parity data portions, determining a new parity based on the new data and the missing non-parity data portions, and writing, in response to verifying the coherency of the missing non-parity data portions, the new data and the new parity to a RAID group without writing the one or more missing non-parity data portions to the RAID group, wherein the new data and the new parity are written to the RAID group with a checksum.

First claim

What is claimed is:

1. A computer-implemented method, comprising:
receiving a write request comprising new data to be written to a data storage system, wherein the data storage system comprises a plurality of data storage devices arranged in a redundant array of independent disks (RAID) group;
in response to receiving the write request, determining a size of the write request, wherein the size of the write request equates to half or more non-parity data portions in a full stripe of data but less than all of the non-parity data portions in the full stripe of data; and
based on the size of the write request, performing a process, comprising: reading a parity and one or more missing non-parity data portions in the full stripe of data; verifying the coherency of the one or more missing non-parity data portions by comparing a checksum of the parity and a checksum of the one or more missing non-parity data portions; determining a new parity based on the new data and the one or more missing non-parity data portions; and writing, in response to verifying the coherency of the missing non-parity data portions, the new data and the new parity to the RAID group in the data storage system without writing the one or more missing non-parity data portions to the RAID group in the data storage system, wherein the new data and the new parity are written to the RAID group with a checksum.

2. An apparatus, comprising:
memory; and
processing circuitry coupled to the memory, the memory storing instructions which, when executed by the processing circuitry, cause the processing circuitry to:
receive a write request comprising new data to be written to a data storage system, wherein the data storage system comprises a plurality of data storage devices arranged in a redundant array of independent disks (RAID) group;
in response to receiving the write request, determine a size of the write request, wherein the size of the write request equates to half or more non-parity data portions in a full stripe of data but less than all of the non-parity data portions in the full stripe of data; and
based on the size of the write request, perform a process, comprising: reading a parity and one or more missing non-parity data portions in the full stripe of data; verifying the coherency of the one or more missing non-parity data portions by comparing a checksum of the parity and a checksum of the one or more missing non-parity data portions; determining a new parity based on the new data and the one or more missing non-parity data portions; and writing, in response to verifying the coherency of the missing non-parity data portions, the new data and the new parity to the RAID group in the data storage system without writing the one or more missing non-parity data portions to the RAID group in the data storage system, wherein the new data and the new parity are written to the RAID group with a checksum.

3. A computer program product having a non-transitory computer readable medium which stores a set of instructions, the set of instructions, when carried out by processing circuitry, causing the processing circuitry to perform a method of:
receiving a write request comprising new data to be written to a data storage system, wherein the data storage system comprises a plurality of data storage devices arranged in a redundant array of independent disks (RAID) group;
in response to receiving the write request, determining a size of the write request, wherein the size of the write request equates to half or more non-parity data portions in a full stripe of data but less than all of the non-parity data portions in the full stripe of data; and
based on the size of the write request, performing a process, comprising: reading a parity and one or more missing non-parity data portions in the full stripe of data; verifying the coherency of the one or more missing non-parity data portions by comparing a checksum of the parity and a checksum of the one or more missing non-parity data portions; determining a new parity based on the new data and the one or more missing non-parity data portions; and writing, in response to verifying the coherency of the missing non-parity data portions, the new data and the new parity to the RAID group in the data storage system without writing the one or more missing non-parity data portions to the RAID group in the data storage system, wherein the new data and the new parity are written to the RAID group with a checksum.

Assignees

• Emc Ip Holding Co Llc

Inventors

• Cassano Marc
• Foley Robert
• Cummins Daniel
• Heng Socheavy

Classifications

• G06F11/1076 Primary

  Parity data used in redundant arrays of independent storages, e.g. in RAID systems · CPC title