Data processing method and apparatus, and shared storage device

Patent metadata

Field	Value
Publication number	US-9952783-B2
Application number	US-201514599673-A
Country	US
Kind code	B2
Filing date	Jan 19, 2015
Priority date	Jul 17, 2012
Publication date	Apr 24, 2018
Grant date	Apr 24, 2018

Abstract

A data processing method and apparatus, and a shared storage device, where the method includes receiving, by a shared storage device, a copy-on-write request sent by another storage device, where the copy-on-write request includes data on which copy-on-write is to be performed and a logical unit identifier and snapshot time point of the data; storing the data; and searching, according to the logical unit identifier and snapshot time point of the data, a preset shared mapping table for a corresponding entry, and storing, in the corresponding entry, mapping entry information of the data, where the mapping entry information includes the logical unit identifier and snapshot time point of the data and a storage address that is of the data and in the shared storage device, which can improve efficiency of snapshot data processing.

First claim

What is claimed is:

1. A data processing method comprising:
storing, by a first storage device, a first data and a third data, wherein the first data is data on which a first copy-on-write action is to be performed at a first snapshot point, wherein the third data is data on which a second copy-on-write action is to be performed at a third snapshot point, and wherein the first data is data in a first logical unit of a production volume in a second storage device corresponding to a first logical unit identifier before overwritten by the third data;
receiving, by the first storage device, a first read request for reading a second data, wherein the first read request comprises the first logical unit identifier and a second snapshot time point;
determining, by the first storage device, a copy-on-write action is not to be performed on the second data in the first logical unit at the second snapshot time point and the second data stored in the first logical unit at the second snapshot time point is the same as the third data of the first logical unit when the first logical unit identifier and the second snapshot time point fails to match a mapping entry information item in a mapping table and when the second copy-on-write is performed at the third snapshot time point, wherein the mapping table is used to store mapping entry information for data on which a copy-on-write action needs to be performed and the data is generated by a same production volume, wherein a first entry of the mapping table comprises a first mapping entry information and a second mapping entry information, wherein the first mapping entry information comprises the first logical unit identifier, a first snapshot time point and a first storage address of the first data in the first storage device, wherein the second mapping entry information comprises the first logical unit identifier, the third snapshot time point, and a third storage address of the third data in the first storage device, and wherein the second snapshot time point is later than the first snapshot time point and earlier than the third snapshot time point; and
reading, by the first storage device, the third data from the first, storage device according to the third storage address in the second mapping entry information, wherein mapping entry information items with the first logical unit identifier in the mapping table are arranged in ascending order according to their snapshot time points, and wherein the third snapshot time point in the second mapping entry information is an earliest snapshot time point among any snapshot time points of the mapping entry information items in the first entry after the second snapshot time point.

2. The method according to claim 1 further comprising:
receiving, by the first storage device, a second read request for reading the first data, wherein the second read request comprises the first logical unit identifier and the first snapshot time point of the first data; and
reading, by the first storage device, the first data from the first storage device according to the first storage address in the first mapping entry information when the first mapping entry information matches the first logical unit identifier and the first snapshot time point of the first data.

3. The method according to claim 1 , further comprising:
receiving, by the first storage device, a snapshot copy creation request from a third storage device for creating a snapshot copy of the third data, wherein the snapshot copy creation request comprises the third snapshot time point of the third data;
acquiring, by the first storage device and from the mapping table, the second mapping entry information corresponding to the third snapshot time point of the third data; and
sending, by the first storage device, the third data pointed to by the second mapping entry information to the third storage device.

4. The method according to claim 1 further comprising:
receiving, by the first storage device, a snapshot disabling request for disabling snapshot data, wherein the snapshot disabling request comprises the first snapshot time point;
acquiring, by the first storage device and from the mapping table, the first mapping entry information corresponding to the first snapshot time point; and
disabling, by the first storage device, the first data pointed to by the first mapping entry information after a sharing is completed when the first data pointed to by the first mapping entry information is being shared,
wherein the first data is shared when a mapping entry information item with the first logical unit identifier and a snapshot time point later than the first snapshot time point exists in the mapping table.

5. The method according to claim 4 , wherein the first data pointed to by the first mapping entry information is not shared when a mapping entry information item with the first logical unit identifier and a snapshot time point earlier than the first snapshot time point exists in the mapping table.

6. A storage device comprising:
a first storage device configured to store copy-on-write data from a second storage device; and
a processor coupled to the first storage device and configured to:
store a first data and a third data, wherein the first data is data on which a first copy-on-write action is to be performed at a first snapshot point, wherein the third data is data on which a second copy-on-write action is to be performed at a third snapshot point, and wherein the first data is data in a first logical unit of a production volume in a second storage device corresponding to a first logical unit identifier before overwritten by the third data:
receive a first read request for reading a second data, wherein the first read request comprises the first logical unit identifier and a second snapshot time point; and
determine a copy-on-write action is not to be performed on the second data in the first logical unit at the second snapshot time point and the second data stored in the first logical unit at the second snapshot time point is the same as the third data of the first logical unit when the first logical unit identifier and the second snapshot time point fails to match a mapping entry information item in a mapping table and when the second copy-on-write is performed at the third snapshot time point, wherein the mapping table is used to store mapping entry information for data on which a copy-on-write action needs to be performed and the data is generated by a same production volume, wherein a first entry of the mapping table comprises a first mapping entry information and a second mapping entry information, wherein the first mapping entry information comprises the first logical unit identifier, a first snapshot time point, and a first storage address of the first data in the first storage device, wherein the second mapping entry information comprises the first logical unit identifier, the third snapshot time point, and a third storage address of the third data in the first storage device, and wherein the second snapshot time point is later than the first snapshot time point and earlier than the third snapshot time point; and
read the third data from the first storage device according to the third storage address in the second mapping entry information when, wherein mapping entry information items with the first logical unit identifier in the mapping table are arranged in ascending order according to their snapshot time points, and wherein the third snapshot time point in the second mapping entry information is an earliest snapshot time point among any snapshot, time points of the mapping entry information items in the first entry after a second time point.

7. The storage device according to claim 6 , wherein the processor is further configured to:

Assignees

• Huawei Tech Co Ltd

Inventors

• Lu Cheng
• Yang Bin
• Zou Ye

Classifications

• G06F3/061 Primary

  Improving I/O performance · CPC title

• G06F3/0674

  Disk device · CPC title

• G06F3/0619 Primary

  in relation to data integrity, e.g. data losses, bit errors · CPC title

• G06F17/30634

  Physics · mapped topic

• G06F3/065

  Replication mechanisms · CPC title