Storage management method, electronic device, and computer program product
Storage management techniques involve, in response to a request to write data to a redundant array of independent disks (RAID), determining whether there is an offline disk in a plurality of storage disks constituting the RAID, the RAID comprising a plurality of stripes, each of the plurality of stripes comprising a plurality of storage blocks divided from the plurality of storage disks; in response to determining that there is an offline disk in the plurality of storage disks, selecting a target stripe from the plurality of stripes, the target stripe having a storage block allocated from the offline disk for storing parity information; and writing the data to the target stripe. In this way, the performance of data write can be improved in presence of an offline disk. In addition, the performance of subsequent data read can also be improved potentially.
1. A method of storage management, comprising:
in response to a request to write data to a redundant array of independent disks (RAID), determining whether there is an offline disk in a plurality of storage disks constituting the RAID, the RAID comprising a plurality of stripes, each of the plurality of stripes comprising a plurality of storage blocks divided from the plurality of storage disks;
in response to determining that there is an offline disk in the plurality of storage disks, selecting a target stripe from the plurality of stripes, the target stripe having a storage block allocated from the offline disk for storing parity information; and
writing the data to the target stripe.
2. The method of claim 1 , wherein selecting the target stripe comprises:
determining a writable RAID storage block from the RAID, the RAID storage block comprising a predetermined number of stripes of the plurality of stripes;
determining free stripes from the RAID storage block; and
selecting the target stripe from the free stripes.
3. The method of claim 2 , wherein selecting the target stripe from the free stripes comprises:
determining at least one of the free stripes that has a storage block allocated from the offline disk for storing parity information, based on stripe layout information of the RAID and a relative position of the offline disk among the plurality of storage disks; and
selecting the target stripe from the at least one determined free stripe.
4. The method of claim 3 , wherein the stripe layout information comprises used capacity of the RAID storage block, per-stripe capacity, a stripe width, and a distribution pattern of storage blocks for storing parity information among respective stripes.
5. The method of claim 1 , wherein writing the data to the target stripe comprises:
writing the data to other storage blocks in the target stripe than the storage block from the offline disk, without generating parity information of the data.
6. The method of claim 1 , further comprising:
in response to a further request to read at least one portion of the data, directly reading the at least one portion of the data from the target stripe.
7. An electronic device, comprising:
at least one processor; and
at least one memory storing computer program instructions, the at least one memory and the computer program instructions being configured, with the at least one processor, to cause the electronic device to perform acts comprising:
in response to a request to write data to a redundant array of independent disks (RAID), determining whether there is an offline disk in a plurality of storage disks constituting the RAID, the RAID comprising a plurality of stripes each comprising a plurality of storage blocks divided from the plurality of storage disks;
in response to determining that there is an offline disk in the plurality of storage disks, selecting a target stripe from the plurality of stripes, the target stripe having a storage block allocated from the offline disk for storing parity information; and
writing the data to the target stripe.
8. The device of claim 7 , wherein selecting the target stripe comprises:
determining a writable RAID storage block from the RAID, the RAID storage block comprising a predetermined number of stripes of the plurality of stripes;
determining free stripes from the RAID storage block; and
selecting the target stripe from the free stripes.
9. The device of claim 8 , wherein selecting the target stripe from the free stripes comprises:
determining at least one of the free stripes that has a storage block allocated from the offline disk for storing parity information, based on stripe layout information of the RAID and a relative position of the offline disk among the plurality of storage disks; and
selecting the target stripe from the at least one determined free stripe.
10. The device of claim 9 , wherein the stripe layout information comprises used capacity of the RAID storage block, per-stripe capacity, a stripe width, and a distribution pattern of storage blocks for storing parity information among respective stripes.
11. The device of claim 7 , wherein writing the data to the target stripe comprises:
writing the data to other storage blocks in the target stripe than the storage block from the offline disk, without generating parity information of the data.
12. The device of claim 7 , wherein the acts further comprise:
in response to a further request to read at least one portion of the data, directly reading the at least one portion of the data from the target stripe.
13. A computer program product being tangibly stored on a non-transitory computer readable medium and comprising machine executable instructions, the machine executable instructions, when executed, causing a device to:
in response to a request to write data to a redundant array of independent disks (RAID), determine whether there is an offline disk in a plurality of storage disks constituting the RAID, the RAID comprising a plurality of stripes each comprising a plurality of storage blocks divided from the plurality of storage disks;
in response to determining that there is an offline disk in the plurality of storage disks, select a target stripe from the plurality of stripes, the target stripe having a storage block allocated from the offline disk for storing parity information; and
write the data to the target stripe.
14. The computer program product of claim 13 , wherein the machine executable instructions, when executed, cause the device to:
determine a writable RAID storage block from the RAID, the RAID storage block comprising a predetermined number of stripes of the plurality of stripes;
determine free stripes from the RAID storage block; and
select the target stripe from the free stripes.
15. The computer program product of claim 14 , wherein the machine executable instructions, when executed, cause the device to:
determine at least one of the free stripes that has a storage block allocated from the offline disk for storing parity information, based on stripe layout information of the RAID and a relative position of the offline disk among the plurality of storage disks; and
select the target stripe from the at least one determined free stripe.
16. The computer program product of claim 15 , wherein the stripe layout information comprises used capacity of the RAID storage block, per-stripe capacity, a stripe width, and a distribution pattern of storage blocks for storing parity information among respective stripes.
17. The computer program product of claim 13 , wherein the machine executable instructions, when executed, cause the device to:
write the data to other storage blocks in the target stripe than the storage block from the offline disk, without generating parity information of the data.
18. The computer program product of claim 13 , wherein the machine executable instructions, when executed, further cause the device to:
in response to a further request to read at least one portion of the data, directly read the at least one portion of the data from the target stripe.