Method, device and computer program product for processing disk unavailability states
Techniques for managing data involve determining multiple indications related to a status of a stripe, including a first indication to indicate whether a group of disks related to the stripe is available, a second indication to indicate whether to rebuild the stripe, and a third indication to retain a value of the first indication when a disk is unavailable; in response to detecting that a disk in the group of disks is unavailable, updating the first indication to indicate that the disk is unavailable; and in response to receiving a write operation, determining an updating to the third indication with a first value of the updated first indication; and in response to determining that the unavailable disk is available again within a predetermined time period, updating the second indication with a current value of the updated third indication, to indicate rebuilding of the stripe.
1. A method of managing data, comprising:
determining multiple indications related to a status of a stripe, the multiple indications including a first indication indicating whether a group of disks related to the stripe is available, a second indication indicating whether to rebuild the stripe, and a third indication maintaining, upon receipt of a write operation, a value of the first indication when the group of disks is unavailable, each of the first indication, the second indication, and the third indication having an initial value;
in response to detecting that the group of disks is unavailable, updating the first indication with a first value to indicate that the group of disks is unavailable;
in response to receiving a read operation when the group of disks is unavailable, maintaining the initial value of the third indication unchanged;
in response to receiving a write operation when the group of disks is unavailable, updating the third indication with the first value of the updated first indication;
in response to determining that the unavailable group of disks is available again within a predetermined time period;
updating the second indication with a current value of the third indication;
in response to the second indication being updated with the current value equal to the initial value, avoiding rebuilding the stripe; and
in response to the second indication being updated with the current value different from the initial value, rebuilding of the stripe; and
in response to determining that the unavailable group of disks is not available again in the predetermined time period:
allocating a new disk slice for the stripe;
updating the second indication with the first value of the updated first indication; and
rebuilding the stripe.
2. The method according to claim 1 , wherein updating the third indication with the first value of the updated first indication comprises:
in response to receiving the write operation, determining whether the first value and the current value of the third indication are the same; and
in response to determining that the first value is different from the current value;
putting the write operation into a queue;
updating the third indication with the first value; and
fetching the write operation from the queue to perform the write operation.
3. The method according to claim 2 , wherein updating the third indication with the first value of the updated first indication comprises:
in response to determining that the first value is equal to the current value, performing the write operation.
4. The method according to claim 1 , wherein the updated second indication having the initial value indicates the stripe does not need to be rebuilt.
5. An electronic device for managing data, comprising:
a processor; and
a memory storing computer program instructions, the processor running the computer program instructions in the memory to control the electronic device to perform acts comprising:
determining multiple indications related to a status of a stripe, the multiple indications including a first indication indicating whether a group of disks related to the stripe is available, a second indication indicating whether to rebuild the stripe, and a third indication maintaining, upon receipt of a write operation, a value of the first indication when the group of disks is unavailable, each of the first indication, the second indication, and the third indication having an initial value;
in response to detecting that the group of disks is unavailable, updating the first indication with a first value to indicate that the group of disks is unavailable;
in response to receiving a read operation when the group of disks is unavailable, maintaining the initial value of the third indication unchanged;
in response to receiving a write operation when the group of disks is unavailable, updating the third indication with the first value of the updated first indication;
in response to determining that the unavailable group of disks is available again within a predetermined time period;
updating the second indication with a current value of the third indication;
in response to the second indication being updated with the current value equal to the initial value, avoiding rebuilding the stripe; and
in response to the second indication being updated with the current value different from the initial value, rebuilding of the stripe; and
in response to determining that the unavailable group of disks is not available again in the predetermined time period:
allocating a new disk slice for the stripe;
updating the second indication with the first value of the updated first indication; and
rebuilding the stripe.
6. The electronic device according to claim 5 , wherein updating the third indication with the first value of the updated first indication comprises:
in response to receiving the write operation, determining whether the first value and the current value of the third indication are the same; and
in response to determining that the first value is different from the current value;
putting the write operation into a queue;
updating the third indication with the first value; and
fetching the write operation from the queue to perform the write operation.
7. The electronic device according to claim 6 , wherein updating the third indication with the first value of the updated first indication comprises:
in response to determining that the first value is equal to the current value, performing the write operation.
8. The electronic device according to claim 5 , wherein the updated second indication having the initial value indicates that the stripe does not need to be rebuilt.
9. A computer program product having a non-transitory computer readable medium which stores a set of instructions to manage data; the set of instructions, when carried out by computerized circuitry, causing the computerized circuitry to perform a method of:
determining multiple indications related to a status of a stripe, the multiple indications including a first indication indicating whether a group of disks related to the stripe is available, a second indication indicating whether to rebuild the stripe, and a third indication maintaining, upon receipt of a write operation, a value of the first indication when the group of disks is unavailable, each of the first indication, the second indication, and the third indication having an initial value;
in response to detecting that the group of disks is unavailable, updating the first indication with a first value to indicate that the group of disks is unavailable;
in response to receiving a read operation when the group of disks is unavailable, maintaining the initial value of the third indication unchanged;
in response to receiving a write operation when the group of disks is unavailable, updating the third indication with the first value of the updated first indication;
in response to determining that the unavailable group of disks is available again within a predetermined time period;
updating the second indication with a current value of the third indication;
in response to the second indication being updated with the current value equal to the initial value, avoiding rebuilding the stripe; and
in response to the second indication being updated with the current value different from the initial value, rebuilding of the stripe; and
in response to determining that the unavailable group of disks is not available again in the predetermined time period:
allocating a new disk slice for the stripe;
updating the second indication with the first value of the updated first indication; and
rebuilding the stripe.
10. The computer program product according to claim 9 , wherein updating the third indication with the first value of the updated first indication comprises:
in response to receiving the write operation, determining whether the first value and the current value of the third indication are the same; and
in response to determining that the first value is different from the current value:
putting the write operation into a queue;
updating the third indication with the first value; and
fetching the write operation from the queue to perform the write operation.
11. The computer program product according to claim 10 , wherein updating the third indication with the first value of the updated first indication comprises:
in response to determining that the first value is equal to the current value, performing the write operation.
12. The computer program product according to claim 9 , wherein the updated second indication having the initial value indicates the stripe does not need to be rebuilt.