Metadata management during an intermediate persistent storage failure during startup

Patent metadata

Field	Value
Publication number	US-12430063-B2
Application number	US-202318225387-A
Country	US
Kind code	B2
Filing date	Jul 24, 2023
Priority date	Jan 19, 2023
Publication date	Sep 30, 2025
Grant date	Sep 30, 2025

Abstract

Techniques for storing metadata involve: storing first metadata associated with a system operation in a volatile memory of a storage system while the storage system is in a startup stage. The storage system does not perform read/write requests of a client during the startup stage. Such techniques further involve: suspending the system operation of the storage system during the startup stage in response to determining that the intermediate persistent storage device has failed. Such techniques further involve: storing the first metadata in the volatile memory into the persistent storage device. Such techniques further involve: storing the first metadata into the intermediate persistent storage device in response to determining that the intermediate persistent storage device is available again. Accordingly, the risk of losing metadata when the storage device is powered down can be reduced.

First claim

The invention claimed is:

1. A method for storing metadata, comprising:
performing, by a storage system during an initialization stage after the storage system restarts, one or more initialization operations for initializing one or more data path (DP) components in a data path of the storage system, the one or more DP components being configured to perform a plurality of read/write operations within the storage system, the one or more initialization operations including generating first metadata associated with the initializing of the one or more DP components;
storing the first metadata in a volatile memory of the storage system while the storage system is in the initialization stage, wherein the first metadata is to be transferred from the volatile memory to an intermediate persistent storage device of the storage system, and data in the intermediate persistent storage device is to be flushed to a persistent storage device of the storage system;
in response to determining that the intermediate persistent storage device has failed, preventing the one or more initialization operations from generating additional first metadata by suspending the initializing of the one or more DP components;
storing the first metadata in the volatile memory into the persistent storage device; and
storing the first metadata into the intermediate persistent storage device in response to determining that the intermediate persistent storage device is available.

2. The method according to claim 1 , wherein storing the first metadata into the persistent storage device further comprises:
configuring the persistent storage device in the storage system to cause the persistent storage device to perform read/write requests only for storage space in the persistent storage device that is used to store dirty data.

3. The method according to claim 1 , wherein the volatile memory of the storage system further stores user data, and wherein the method further comprises:
discarding the user data in the volatile memory during a startup stage in response to determining that the intermediate persistent storage device has failed.

4. The method according to claim 3 , further comprising:
storing the user data in the persistent storage device into the intermediate persistent storage device in response to determining that the intermediate persistent storage device is available again,
wherein the user data stored in the persistent storage device was transferred from the volatile memory to the persistent storage device when the intermediate persistent storage device failed prior to the startup stage.

5. The method according to claim 4 , further comprising:
flushing the first metadata and the user data stored in the intermediate persistent storage device to the persistent storage device.

6. The method according to claim 5 , further comprising:
resuming the initializing of the one or more DP components in response to determining that all metadata in the persistent storage device is stored in the volatile memory.

7. The method according to claim 1 , further comprising:
suspending, by the storage system, a read/write operation from among the plurality of read/write operations in response to determining that the intermediate persistent storage device has failed; and
storing second metadata in the volatile memory into the persistent storage device.

8. The method according to claim 1 , wherein suspending the initializing of the one or more DP components comprises:
waiting for a completion, suspension, or failure of a current transaction performed in the storage system.

9. An electronic device, comprising:
a controller; and
a volatile memory coupled to the controller, the volatile memory having instructions stored therein, wherein the instructions, when executed by the controller, cause the electronic device to perform actions comprising:
performing, by a storage system during an initialization stage after the storage system restarts, one or more initialization operations for initializing one or more data path (DP) components in a data path of the storage system, the one or more DP components being configured to perform a plurality of read/write operations within the storage system, the one or more initialization operations including generating first metadata associated with the initializing of the one or more DP components;
storing the first metadata in the volatile memory while the storage system is in the initialization stage, wherein the first metadata is to be transferred from the volatile memory to an intermediate persistent storage device of the storage system, and data in the intermediate persistent storage device is to be flushed to a persistent storage device of the storage system;
in response to determining that the intermediate persistent storage device has failed, preventing the one or more initialization operations from generating additional first metadata by suspending the initializing of the one or more DP components;
storing the first metadata in the volatile memory into the persistent storage device; and
storing the first metadata into the intermediate persistent storage device in response to determining that the intermediate persistent storage device is available.

10. The electronic device according to claim 9 , wherein storing the metadata into the volatile memory further comprises:
configuring the persistent storage device in the storage system to cause the persistent storage device to perform read/write requests only for storage space in the persistent storage device that is used to store dirty data.

11. The electronic device according to claim 9 , wherein the volatile memory of the storage system further stores user data, and wherein the actions further comprise:
discarding the user data in the volatile memory during a startup stage in response to determining that the intermediate persistent storage device has failed.

12. The electronic device according to claim 11 , wherein the actions further comprise:
storing the user data in the persistent storage device into the intermediate persistent storage device in response to determining that the intermediate persistent storage device is available again,
wherein the user data stored in the persistent storage device was transferred from the volatile memory to the persistent storage device when the intermediate persistent storage device failed prior to the startup stage.

13. The electronic device according to claim 12 , wherein the actions further comprise:
flushing the first metadata and the user data stored in the intermediate persistent storage device to the persistent storage device.

14. The electronic device according to claim 13 , wherein the actions further comprise:
resuming the initializing of the one or more DP components in response to determining that all metadata in the persistent storage device is stored in the volatile memory.

15. The electronic device according to claim 9 , wherein the actions further comprise:
suspending, by the storage system, a read/write operation from among the plurality of read/write operations in response to determining that the intermediate persistent storage device has failed; and
storing second metadata in the volatile memory into the persistent storage device.

16. The electronic device according to claim 9 , wherein suspending the initializing of the one or more DP components comprises:
waiting for a completion, suspension, or failure of a current transaction performed in the storage system.

17. A computer program product, the computer program product being tangibly stored on a

Assignees

• Dell Products Lp

Inventors

• Yang Yue
• Liu Yousheng
• Ma Chun

Classifications

• G06F3/0604 Primary

  Improving or facilitating administration, e.g. storage management · CPC title

• G06F3/0673

  Single storage device · CPC title

• G06F11/0787

  Storage of error reports, e.g. persistent data storage, storage using memory protection · CPC title

• G06F3/0679

  Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP] · CPC title

• G06F3/0655 Primary

  Vertical data movement, i.e. input-output transfer; data movement between one or more hosts and one or more storage devices · CPC title