Data access method, apparatus and computer program product
AssigneeEMC IP Holding Company LLC
InventorsJibing Dong, Jian Gao
Life of this patent
Estimating the term…
Abstract
Techniques perform data access to a disk array. The disk array includes a parity disk and a plurality of data disks. Via such techniques, data is written to the parity disk in the disk array in response to a write request to a failed data disk in the disk array when the disk array is in a degraded state; and corresponding degraded storage position information is set in disk resource mapping information so as to indicate that the data are stored in the parity disk. Accordingly, enormous computing resources can be saved, and I/O operations required by reads in the degraded state can be reduced.
Claims16
A method for performing data access to a disk array, wherein the disk array comprises a parity disk and a plurality of data disks, the method comprising:
- writing data to the parity disk in the disk array in response to a write request to a failed data disk in the disk array when the disk array is in a degraded state;
- setting corresponding degraded storage position information in disk resource mapping information so as to indicate that the data are stored in the parity disk;
- calculating parity information for the data in response to the disk array returning to an optimized state;
- and
- storing the parity information in the failed data disk which has been recovered.
An apparatus for performing data access to a disk array, wherein the disk array comprises a parity disk and a plurality of data disks, the apparatus comprising:
- a processor;
- and
- a memory coupled to the processor and having instructions stored therein, the instructions, when executed by the processor, causing the apparatus to perform acts comprising:
- writing data to the parity disk in the disk array in response to a write request to a failed data disk in the disk array when the disk array is in a degraded state;
- setting corresponding degraded storage position information in disk resource mapping information so as to indicate that the data are stored in the parity disk;
- calculating parity information for the data in response to the disk array returning to an optimized state;
- and
- storing the parity information in the failed data disk which has been recovered.
A computer program product having a non-transitory computer readable medium which stores a set of instructions to perform data access to a disk array, wherein the disk array includes a parity disk and a plurality of data disks;
- the set of instructions, when carried out by computerized circuitry, causing the computerized circuitry to perform a method of:
- writing data to the parity disk in the disk array in response to a write request to a failed data disk in the disk array when the disk array is in a degraded state;
- and
- setting corresponding degraded storage position information in disk resource mapping information so as to indicate that the data are stored in the parity disk,
- wherein the disk resource mapping information comprises a plurality of degraded storage position indicators for each of the plurality of data disks, and
- wherein the setting corresponding degraded position information in the disk resource mapping information comprises setting in the disk resource mapping information a degraded storage position indicator corresponding to the failed data disk.
Dependencies are inferred from the claim text.