Storage apparatus and data management method in storage apparatus
AssigneeHitachi, Ltd.
InventorNaoki Moritoki
Life of this patent
Estimating the term…
Abstract
Provided are a storage apparatus and its data management method capable of preventing the loss of data retained in a volatile cache memory even during an unexpected power shutdown. This storage apparatus includes a cache memory configured from a volatile and nonvolatile memory. The volatile cache memory caches data according to a write request from a host system and data staged from a disk drive, and the nonvolatile cache memory only caches data staged from a disk drive. Upon an unexpected power shutdown, the storage apparatus immediately backs up the dirty data and other information cached in the volatile cache memory to the nonvolatile cache memory.
Claims13
A storage apparatus comprising:
- a disk drive having a storage medium for storing a plurality of data sets;
- and
- a disk controller configured to control the disk drive, wherein the disk controller comprises:
- a host interface configured to receive an I/O request from a host system;
- a disk interface operatively connected to the disk drive;
- and
- a cache mechanism operatively connected to the host interface and the disk interface and having a first cache memory configured from a volatile memory and a second cache memory configured from a nonvolatile memory,
- wherein the disk controller is configured to manage a plurality of attribute values associated with the plurality of data sets stored in the disk drive,
- wherein the plurality of attribute values are values based on a frequency of the access request to the data set,
- wherein, when the access request is a read request, the disk controller increases the attribute value associated with the data set according to the read request,
- wherein, when the access request is a write request, the disk controller decreases the attribute value associated with the data set according to the write request,
- wherein the disk interface writes one or more first data sets specified from the plurality of data sets stored in the disk drive into the second cache memory based on the plurality of attribute values, and
- wherein, in accordance with a backup request, the disk controller transfers a second data set specified from the first data sets written in the first cache memory to the second cache memory.
A method of managing data in a storage apparatus including a disk drive having a storage medium for storing a plurality of data sets, and a disk controller configured to control the disk drive, the method comprising:
- providing a first cache memory configured from a volatile memory and a second cache memory configured from a nonvolatile memory;
- giving attribute values to the plurality of data sets, respectively, stored in the disk drive,
- wherein the attribute values are values based on a frequency of the access request to the data set;
- increasing, when the access request is a read request, the attribute value associated with the data set according to the read request;
- decreasing, when the access request is a write request, the attribute value associated with the data set according to the write request;
- writing a first data set in the first cache memory;
- specifying a second data set from the plurality of data sets stored in the disk drive based on the attribute values;
- writing the specified data set into the second cache memory;
- determining, upon receiving a write request from a host system, whether a corresponding data set to a data set according to the write request has been written as the second data set into the second cache memory;
- invalidating an area in which the second data set was written in the second cache memory when it is determined that the corresponding data set to the data set according to the write request has been written as the second data set into the second cache memory;
- writing an alternative data set to be specified based on the attribute values into the invalidated area in the second cache memory;
- and
- transferring, in accordance with a backup request, the first data set written into the first cache memory to the second cache memory.
A method of managing data in a storage apparatus including a plurality of disk drives having a storage medium for storing a data set, and a disk controller configured to control the plurality of disk drives, the method comprising:
- storing different data sets to each of the plurality of disk drives;
- giving attribute values to each of the data sets;
- rearranging the data sets in the plurality of disk drives based on the given attribute values;
- specifying at least one disk drive among the plurality of disk drives;
- writing all of the data sets rearranged in the at least one specified disk drive into a cache memory configured from a nonvolatile memory;
- and
- stopping power delivery to the at least one specified disk drive.
Dependencies are inferred from the claim text.