Storage control unit and data management method
AssigneeHitachi, Ltd.
InventorsJunichi Iida, Xiaoming Jiang
Life of this patent
Estimating the term…
Abstract
An I/O processor determines whether or not the amount of dirty data on a cache memory exceeds a threshold value and, if the determination is that this threshold value has been exceeded, writes a portion of the dirty data of the cache memory to a storage device. If a power source monitoring and control unit detects a voltage abnormality of the supplied power, the power monitoring and control unit maintains supply of power using power from a battery, so that a processor receives supply of power from the battery and saves the dirty data stored on the cache memory to a non-volatile memory.
Claims20
A storage control unit that, on receipt of a write access request from an external unit, performs control of writing, to a storage unit, of data that is the subject of the write access request, the storage control unit comprising:
- a power supply unit that performs supply of power from a power source;
- a battery that stores power so that power can be supplied;
- a cache memory constituted by a volatile memory capable of storing data when supplied with power;
- a non-volatile memory capable of continuing to store data even without power supplied thereto;
- a request reception unit that receives the write access request when supplied with said power;
- a first data storage unit that stores data that is the subject of said write access request in said cache memory as cache data;
- a determination unit that determines whether or not the amount of dirty data, of said cache data in said cache memory, that has not been reflected to said storage unit, exceeds a prescribed threshold value;
- a second data storage unit that, if the determination is that said threshold value has been exceeded, stores at least a portion of said dirty data of said cache memory in said storage unit;
- a power source monitoring unit that detects a voltage abnormality of the power that is supplied from said power supply unit;
- a save storage unit that saves in said non-volatile memory the dirty data stored in said cache memory on receipt of supply of said power from said battery, if said voltage abnormality is detected by said power source monitoring unit;
- and
- a power source supply control unit that maintains supply of power to said cache memory and said save storage unit using the power from said battery if said voltage abnormality is detected by said power source monitoring unit.
A method of data management using a storage control unit that, on receiving a write access request from an external unit, performs control of writing, to a storage unit, data that is the subject of the write access request, wherein
- said storage control unit comprises:
- a power supply unit that supplies power from a power source;
- a battery that stores power so that power can be supplied;
- a cache memory comprising volatile memory capable of storing data when supplied with power;
- a non-volatile memory capable of continuing to store data even when not supplied with power;
- and a power source monitoring unit that detects voltage abnormality of the power supplied from said power supply unit, the method comprising:
- storing the data that is the subject of said write access request in said cache memory as cache data, when the write access request is received,
- determining whether or not the amount of dirty data, of said cache data of said cache memory, that has not been reflected to said recording unit exceeds a prescribed threshold value,
- storing at least a portion of said dirty data of said cache memory in said storage unit, if the determination is that said threshold value is exceeded,
- supplying power to said cache memory from said battery, if said voltage abnormality is detected by said power source monitoring unit, and
- saving the dirty data stored in said cache memory to said non-volatile memory,by supply of said power from said battery.
A storage control unit that, on receiving a write access request from an external unit, performs control of writing, to a storage unit, data that is the subject of the write access request, the storage control unit comprising:
- a power supply circuit that performs supply of power from a power source;
- a battery that stores power so that power can be supplied;
- a cache memory constituted by volatile memory capable of storing data when supplied with power;
- a non-volatile memory capable of continuing to store data even without power supplied thereto;
- an interface that receives the write access request from said external unit;
- a first processor connected with said interface and that is capable of input/output of data with said cache memory;
- a second processor capable of input/output of data between said cache memory and said non-volatile memory;
- and
- a power source monitoring unit that detects voltage abnormality from said power source unit, wherein
- said first processor,
- on receipt of a write access request received by said interface, stores the data that is the subject of said write access request in said cache memory as cache data,
- determines whether or not the amount of dirty data, of said cache data of said cache memory, that has not been reflected to said storage device exceeds a prescribed threshold value, and
- if the determination is that said threshold value has been exceeded, stores at least a portion of said dirty data of said cache memory in said storage unit,
- said second processor,
- if said power source monitoring and control unit detects said voltage abnormality, saves the dirty data stored in said cache memory in said non-volatile memory by receiving supply of said power from said battery, and
- said power source monitoring and control unit, if said voltage abnormality is detected, maintains supply of power to said cache memory and said second processor using the power from said battery.
Dependencies are inferred from the claim text.