Methods, devices and computer readable mediums for managing storage system

1. A method for managing a storage system, the storage system including a disk array which includes at least one disk array group, the method comprising:

in response to receiving a first message indicating that a failure occurs in a disk in the disk array, determining first information on a disk array group that the failed disk belongs to;

obtaining a first number of outstanding input/output (I/O) operations on rebuilding the failed disk in the disk array group;

determining, based on the first information and the first number, a threshold number of I/O operations that is applicable for the disk array group; and

controlling, based on the threshold number, the number of I/O operations initiated to the disk array group;

wherein controlling the number of I/O operations initiated to the disk array group comprises:

in response to receiving a request for a first I/O operation on the disk array group, determining a third number of outstanding I/O operations initiated to the disk array group;

in response to the threshold number exceeding the third number, initiating to the disk array group at least part of first I/O operations; and

in response to initiating the at least part of the first I/O operations, updating the threshold number.

2. The method according to claim 1 , wherein determining the first information on the disk array group that the failed disk comprises:

identifying a logic storage unit corresponding to the disk array group; and

setting a state of the identified logic storage unit from a normal state to a degraded state.

3. The method according to claim 2 , further comprising:

in response to receiving a second message indicating that the failure in the disk array group is removed, setting the state of the logic storage unit from the degraded state back to the normal state.

4. The method according to claim 1 , wherein determining the first information on the disk array group comprises:

obtaining:

a total number of disks in the disk array group;

the number of spare disks for rebuilding the failed disk in the disk array group; and

a second number of I/O operations affordable for each disk in the disk array group.

5. The method according to claim 4 , wherein determining the threshold number of I/O operations that is applicable for the disk array group comprises:

determining the threshold number based on the total number of disks, the number of spare disks, the first number and the second number.

6. The method according to claim 1 , wherein the at least part of the first I/O operations includes a reading operation, and wherein updating the threshold number comprises:

in response to initiating the reading operation, reducing the threshold number by a first predefined number.

7. The method according to claim 1 , wherein the at least part of the first I/O operations includes a writing operation, and wherein updating the threshold number comprises:

in response to initiating the writing operation, reducing the threshold number by a second predefined number.

8. A system, comprising:

a storage system including a disk array which includes at least one disk array group;

computer-executable program logic encoded in memory of one or more computers enabled to manage storage,

wherein the computer-executable program logic is configured for the execution of:

in response to receiving a first message indicating that a failure occurs in a disk in the disk array, determining first information on a disk array group that the failed disk belongs to;

obtaining a first number of outstanding input/output (I/O) operations on rebuilding the failed disk in the disk array group;

determining, based on the first information and the first number, a threshold number of I/O operations that is applicable for the disk array group; and

controlling, based on the threshold number, the number of I/O operations initiated to the disk array group;

wherein controlling the number of I/O operations initiated to the disk array croup comprises:

in response to receiving a request for a first I/O operation on the disk array group, determining a third number of outstanding I/O operations initiated to the disk array group;

in response to the threshold number exceeding the third number, initiating to the disk array group at least part of first I/O operations; and

in response to initiating the at least part of the first I/O operations, updating the threshold number.

9. The system according to claim 8 , wherein determining the first information on the disk array group that the failed disk comprises:

identifying a logic storage unit corresponding to the disk array group; and

setting a state of the identified logic storage unit from a normal state to a degraded state.

10. The system according to claim 9 , wherein the computer-executable program logic is further configured for the execution of:

in response to receiving a second message indicating that the failure in the disk array group is removed, setting the state of the logic storage unit from the degraded state back to the normal state.

11. The system method according to claim 8 , wherein determining the first information on the disk array group comprises:

obtaining:

a total number of disks in the disk array group;

the number of spare disks for rebuilding the failed disk in the disk array group; and

a second number of I/O operations affordable for each disk in the disk array group.

12. The system according to claim 11 , wherein determining the threshold number of I/O operations that is applicable for the disk array group comprises:

determining the threshold number based on the total number of disks, the number of spare disks, the first number and the second number.

13. The system according to claim 8 , wherein the at least part of the first I/O operations includes a reading operation, and wherein updating the threshold number comprises:

in response to initiating the reading operation, reducing the threshold number by a first predefined number.

14. The system according to claim 8 , wherein the at least part of the first I/O operations includes a writing operation, and wherein updating the threshold number further comprises:

in response to initiating the writing operation, reducing the threshold number by a second predefined number.

15. A computer program product for managing a storage system, the storage system including a disk array which includes at least one disk array group, the computer program product comprising:

a non-transitory computer readable medium encoded with computer executable code, the code configured to enable the execution of:

in response to receiving a first message indicating that a failure occurs in a disk in the disk array, determining first information on a disk array group that the failed disk belongs to;

obtaining a first number of outstanding input/output (I/O) operations on rebuilding the failed disk in the disk array group;

determining, based on the first information and the first number, a threshold number of I/O operations that is applicable for the disk array group; and

controlling, based on the threshold number, the number of I/O operations initiated to the disk array group;

wherein controlling the number of I/O operations initiated to the disk array group comprises:

in response to receiving a request for a first I/O operation on the disk array group, determining a third number of outstanding I/O operations initiated to the disk array group;

in response to the threshold number exceeding the third number, initiating to the disk array group at least part of first I/O operations; and

in response to initiating the at least part of the first I/O operations, updating the threshold number.

16. The computer program product according to claim 15 , wherein determining the first information on the disk array group that the failed disk comprises:

identifying a logic storage unit corresponding to the disk array group; and

setting a state of the identified logic storage unit from a normal state to a degraded state.

17. The computer program product according to claim 16 , wherein the code is further configured to enable the execution of:

in response to receiving a second message indicating that the failure in the disk array group is removed, resetting the state of the logic storage unit from the degraded state back to the normal state.

18. The computer program product according to claim 15 , wherein determining the first information on the disk array group comprises:

obtaining:

a total number of disks in the disk array group;

the number of spare disks for rebuilding the failed disk in the disk array group; and

a second number of I/O operations affordable for each disk in the disk array group.

19. The method according to claim 1 , wherein a cache is constructed and arranged to initiate cached I/O operations to the disk array group; and

wherein controlling the number of I/O operations further comprises:

while the disk array group is able to receive cached I/O operations from the cache, delaying initiation at least some of the cached I/O operations from the cache to accelerate rebuilding of the failed disk.

20. The system according to claim 8 , wherein a cache is constructed and arranged to initiate cached I/O operations to the disk array group; and

wherein controlling the number of I/O operations further comprises:

while the disk array group is able to receive cached I/O operations from the cache, delaying initiation at least some of the cached I/O operations from the cache to accelerate rebuilding of the failed disk.

21. The computer program product according to claim 15 , wherein a cache is constructed and arranged to initiate cached I/O operations to the disk array group; and

wherein controlling the number of I/O operations further comprises:

while the disk array group is able to receive cached I/O operations from the cache, delaying initiation at least some of the cached I/O operations from the cache to accelerate rebuilding of the failed disk.