摘要:
A storage system has a control module for controlling a plurality of disk storage devices via a transmission path so as to discern the abnormalities of the plurality of disk devices and those of the transmission paths. When a control module for controlling the plurality of disk storage devices detects an error when the disk storage devices are accessed, the control module dummy-accesses the plurality of the disk storage devices on the transmission path, and specifies the suspected failure location based on the result. Therefore it can be discerned whether the suspected failure location is in the transmission path or the disk drive.
摘要:
A magnetic disk apparatus capable of effectively achieving speedup of the response to a read request, a control method and control program therefore are provided. In a control of a magnetic disk apparatus having a RAID configuration in which the same data is written on two disks, a given algorism is selected from a plurality of different algorisms with respect to the data stored in the disks, read commands are issued to the data stored in the two disks, respectively, according to the selected algorithm and the data that has been read first by the read commands that has been issued to the two disks in a read command issuance step is adopted as read data.
摘要:
To provide a staging method capable of detecting an error in data read from a disk device during staging, a disk array control apparatus 100 includes a data read unit 101 for reading data, a first reference data generation unit 102 for generating first reference data from the read data, a second reference data generation unit 103 for similarly generating second reference data, a true-false determination unit 104 for determining whether or not the data read by the data read unit 101 is correct, and a data write unit 105 for writing data to cache memory.
摘要:
A RAID control apparatus comprises at least a cache memory; an update information management table for storing update information; an update information storage unit for storing, in the update information management table, update information by detecting a data update; a reference value generation unit for generating a reference value expressing a load of a write back processing by using a Small Write method and a Read & Bandwidth Write method based on the update information; a write method determination unit for determining a write method according to the reference value and a write unit for carrying out a write processing, in order to provide a write back method for a RAID apparatus capable of improving a processing speed at the time of updating even in the case of including the processing of updating a part of data stripes.
摘要:
A RAID control apparatus comprises at least a cache memory; an update information management table for storing update information; an update information storage unit for storing, in the update information management table, update information by detecting a data update; a reference value generation unit for generating a reference value expressing a load of a write back processing by using a Small Write method and a Read & Bandwidth Write method based on the update information; a write method determination unit for determining a write method according to the reference value and a write unit for carrying out a write processing, in order to provide a write back method for a RAID apparatus capable of improving a processing speed at the time of updating even in the case of including the processing of updating a part of data stripes.
摘要:
When a write-back request for writing back new data in a cache memory to disk devices forming a redundant configuration of RAID is generated, a write-back processing unit, reserves a parity buffer area in the cache memory, generates new parity, and then, writes the new data and the new parity to the corresponding disk devices. When an error in which the consistency of RAID is broken occurs in a plurality of the disk devices upon write performed by the write-back processing unit, a recovery processing unit reserves, in the cache memory, a cache stripe area storing data of the entire stripe including the new data which is to be written back, and causes the cache control unit to manage it.
摘要:
In a system for dispersively storing data and parity in a plurality of storage devices, information in a first storage device is restored by using information stored in the storage devices other than the first storage device when the first storage device fails. And information in a non-restored area in the first storage device and information in a second storage device are restored by using information stored in the storage devices other than the first and the second storage devices when the second storage device fails while the information in the first storage device is being restored.
摘要:
Storage destination controller devices wherein N number of data strips and M number of parity strips comprised in each stripe are determined so that the parity strips are not continuously stored to the same memory device between two consecutive stripes when a plurality of stripes, each comprising the N number of data strips and the M number of parity strips of different types, are distributed and stored to the N+M number of memory devices.
摘要:
When a write-back request for writing back new data in a cache memory to disk devices forming a redundant configuration of RAID is generated, a write-back processing unit, reserves a parity buffer area in the cache memory, generates new parity, and then, writes the new data and the new parity to the corresponding disk devices. When an error in which the consistency of RAID is broken occurs in a plurality of the disk devices upon write performed by the write-back processing unit, a recovery processing unit reserves, in the cache memory, a cache stripe area storing data of the entire stripe including the new data which is to be written back, and causes the cache control unit to manage it.
摘要:
A method and apparatus for enhancing performance of parity check in computer readable media is provided. For example, in a RAID (N+1) configuration, a virtual data strip is added for a calculation of parity. Data of the virtual data strip is set so that a predetermined portion of a data area in the virtual data strip has a predetermined value. Consequently, performance of parity check performed in a data processing system having a RAID configuration can be enhanced.