Snapshot Processing Method and Related Device

Patent metadata

Field	Value
Publication number	US-2017228181-A1
Application number	US-201715498832-A
Country	US
Kind code	A1
Filing date	Apr 27, 2017
Priority date	Dec 31, 2014
Publication date	Aug 10, 2017
Grant date	—

Abstract

A snapshot processing method includes: receiving a snapshot request command, where the snapshot request command includes an ID of a primary LUN; determining the primary LUN according to the ID of the primary LUN, and setting a snapshot status of the primary LUN to a preparation state; sending a first snapshot command to a mirror storage device, where the first snapshot command includes the ID of the primary LUN, and the first snapshot command is used to notify the mirror storage device that the primary LUN is in the preparation state; receiving a response message, sent by the mirror storage device, of the first snapshot command, where the response message is used to notify the primary storage device that a mirrored LUN is in the preparation state; and performing snapshot processing on the primary LUN.

First claim

What is claimed is:

1 . A method, comprising:
receiving, by a primary storage device, a snapshot request command, wherein the snapshot request command comprises an ID of a primary logical unit (LUN), wherein the primary storage device is comprised in a storage system, the storage system further includes a mirror storage device, both the primary storage device and the mirror storage device are in an operating mode, the primary storage device comprises the primary LUN, and the mirror storage device comprises a mirrored LUN of the primary LUN; determining the primary LUN according to the ID of the primary LUN, and setting a snapshot status of the primary LUN to a preparation state, wherein the preparation state indicates that the primary storage device enters a preparation phase of performing a snapshot on the primary LUN; sending a first snapshot command to the mirror storage device, wherein the first snapshot command comprises the ID of the primary LUN, and notifies the mirror storage device that the primary LUN is in the preparation state; receiving a response message, sent by the mirror storage device, of the first snapshot command, wherein the response message notifies the primary storage device that the mirrored LUN is in the preparation state; and performing the snapshot on the primary LUN.

2 . The method according to claim 1 , wherein after setting the snapshot status of the primary LUN to the preparation state, the method further comprises:
receiving a data write request sent by a host, wherein the data write request comprises service data and the ID of the primary LUN; and after determining, according to the ID of the primary LUN, that the primary LUN is in the preparation state, writing the service data to the primary LUN; and forwarding the data write request to the mirror storage device.

3 . The method according to claim 1 , wherein after setting the snapshot status of the primary LUN to the preparation state, the method further comprises:
receiving a data write request sent by the mirror storage device, wherein the data write request comprises service data and the ID of the mirrored LUN; after determining, according to the ID of the primary LUN, that the primary LUN is in the preparation state, writing the service data to the primary LUN; and sending, to the mirror storage device, a message indicating that the primary storage device has written the service data to the primary LUN and instructing the mirror storage device to write the service data to the mirror storage device.

4 . The method according to claim 1 , wherein after performing the snapshot on the primary LUN, the method further comprises:
setting the snapshot status of the primary LUN to a complete state, wherein the complete state indicates that the primary storage device has completed snapshotting on the primary LUN; sending a second snapshot command to the mirror storage device, wherein the second snapshot command comprises the ID of the primary LUN, and a second snapshot command notifies the mirror storage device that the primary LUN is in the complete state; and receiving a response message, sent by the mirror storage device, of the second snapshot command, wherein the response message notifies the primary storage device that the mirror storage device has completed the snapshot on the mirrored LUN.

5 . A method, comprising:
receiving, by a mirror storage device, a first snapshot command sent by a primary storage device, wherein the mirror storage device is comprised in a storage system, the storage system further comprises a primary storage device, both the primary storage device and the mirror storage device are in an operating mode, the primary storage device comprises a primary logical unit (LUN), and the mirror storage device comprises a mirrored LUN of the primary LUN, wherein the first snapshot command comprises an ID of the primary LUN, and the first snapshot command notifies the mirror storage device that the primary storage device has completed a snapshot on the primary LUN; and performing snapshot processing on the mirrored LUN.

6 . The method according to claim 5 , wherein before receiving the first snapshot command, the method further comprises:
receiving a second snapshot command sent by the primary storage device, wherein the second snapshot command comprises the ID of the primary LUN, and the second snapshot command notifies the mirror storage device that the primary LUN is in a preparation state; determining the mirrored LUN according to the ID of the primary LUN, and setting a snapshot status of the mirrored LUN to the preparation state, wherein the preparation state indicates that the mirror storage device enters a preparation phase of performing snapshot processing on the mirrored LUN; and sending a response message of the second snapshot command to the primary storage device, wherein the response message notifies the primary storage device that the mirrored LUN is in the preparation state.

7 . The method according to claim 5 , further comprising:
receiving a data write request sent by a host, wherein the data write request comprises service data and the ID of the mirrored LUN; forwarding the data write request to the primary storage device; and after receiving a message indicating that the primary storage device has written the service data to the primary LUN, writing the service data to the mirrored LUN.

8 . A primary storage device, comprising:
a memory storing instructions; and a processor coupled to the memory, the processor being configured to execute the instructions to:
receive a snapshot request command, wherein the snapshot request command comprises an ID of a primary logical unit (LUN), wherein the primary storage device is comprised in a storage system, the storage system further includes a mirror storage device, both the primary storage device and the mirror storage device are in an operating mode, the primary storage device comprises the primary logical unit (LUN), and the mirror storage device comprises a mirrored LUN of the primary LUN;
determine the primary LUN according to the ID of the primary LUN, and set a snapshot status of the primary LUN to a preparation state, wherein the preparation state indicates that the primary storage device enters a preparation phase of performing snapshot on the primary LUN;
send a first snapshot command to the mirror storage device, wherein the first snapshot command comprises the ID of the primary LUN, and notifies the mirror storage device that the primary LUN is in the preparation state;
receive a response message, sent by the mirror storage device, of the first snapshot command, wherein the response message notifies the primary storage device that the mirrored LUN is in the preparation state; and
perform a snapshot on the primary LUN.

9 . The storage device according to claim 8 , wherein after the snapshot status of the primary LUN is set to the preparation state, the processor is further configured to execute the instructions to:
receive a data write request sent by a host, wherein the data write request comprises service data and the ID of the primary LUN; write the service data to the primary LUN after the primary LUN is determined in the preparation state; and forward the data write request to the mirror storage device.

10 . The storage device according to claim 8 , wherein after setting the snapshot status of the primary LUN to the preparation state, the processor is further configured to execute the instructions to:
receive a data write request sent by the mirror storage device, wherein the data write request comprises service data and the ID of the mirrored LUN; write the service data to the primary

Assignees

• Huawei Tech Co Ltd

Inventors

• Chen Lei
• Li Xiaohua

Classifications

• G06F11/1446

  Point-in-time backing up or restoration of persistent data · CPC title

• G06F3/0665

  at area level, e.g. provisioning of virtual or logical volumes · CPC title

• G06F3/0619 Primary

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

• G06F3/0659

  Command handling arrangements, e.g. command buffers, queues, command scheduling · CPC title

• G06F11/14

  Error detection or correction of the data by redundancy in operations (error detection or correction of the data by redundancy in hardware G06F11/16) · CPC title