CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Chinese Patent Application No. CN201911240945.X, on file at the China National Intellectual Property Administration (CNIPA), having a filing date of Dec. 6, 2019, and having “METHOD, DEVICE, AND PROGRAM PRODUCT FOR SELECTING REBUILD DESTINATION IN STORAGE SYSTEM” as a title, the contents and teachings of which are herein incorporated by reference in their entirety.

FIELD

Various implementations of the present disclosure relate to management of a storage system, and more specifically, to a method, device and computer program product for selecting a rebuild destination for a failed extent in a storage system.

BACKGROUND

With the development of data storage technology, various data storage devices now provide users with increasingly large data storage capability, and also their data access speed has been greatly improved. With the increase of data storage capability, users also impose higher demands on data reliability and response time of storage systems. So far various data storage systems based on Redundant Arrays of Independent Disks (RAID) have been developed to improve data reliability. When one or more disks in a storage system fail(s), data in failed disk(s) can be recovered from other normal disk(s).

A mapped Redundant Array of Disks has emerged, and storage space may be reserved on a plurality of storage devices in a storage system for rebuilding data in a failed extent in a failed storage device. Basic principles of RAID should be followed during selection of a destination storage device for the failed extent. In other words, it should be ensured that the selected storage device is different from storage devices where other extents in a failed stripe to which the failed extent belong reside. At this point, it has become a focus of research for selecting a rebuild destination for the failed stripe so as to make the best of all reserved storage space in the storage system.

SUMMARY

Therefore, it is desirable to develop and implement a technical solution for managing a storage system more effectively. It is desired that the technical solution be compatible with existing storage systems, and by reconstructing configurations of existing storage systems, selecting a rebuild destination in the storage system will be handled more effectively.

According to a first aspect of the present disclosure, a method is provided for selecting a rebuild destination in a storage system, where the storage system includes a plurality of storage devices. In the method, a group of failed stripes associated with a group of failed extents in a failed storage device among the plurality of storage devices are detected. A group of normal storage devices other than the failed storage device among the plurality of storage devices are determined. Regarding a normal storage device in the group of normal storage devices, a first count for the normal storage device is obtained, the first count representing the number of failed stripes which are allowed to be rebuilt to the normal storage device in the group of failed stripes. Based on the first count, a destination storage device is selected from the group of normal storage devices for rebuilding a failed stripe in the group of failed stripes.

According to a second aspect of the present disclosure, an electronic device is provided, the electronic device including: at least one processor; and a memory coupled to the at least one processor, the memory having instructions stored thereon, the instructions, when executed by the at least one processor, causing the electronic device to perform acts for selecting a rebuild destination in a storage system, which includes a plurality of storage devices. The acts include: detecting a group of failed stripes associated with a group of failed extents in a failed storage device among the plurality of storage devices; determining a group of normal storage devices other than the failed storage device among the plurality of storage devices; regarding a normal storage device in the group of normal storage devices, obtaining a first count for the normal storage device, the first count representing a number of failed stripes which are allowed to be rebuilt to the normal storage device in the group of failed stripes; and selecting, based on the first count, a destination storage device from the group of normal storage devices for rebuilding a failed stripe in the group of failed stripes.

According to a third aspect of the present disclosure, a computer program product is provided. The computer program product is tangibly stored on a non-transitory computer-readable medium and includes machine-executable instructions which are used to implement a method according to the first aspect of the present disclosure.

