Storage system, control method therefor, and program
AssigneeHitachi, Ltd.
InventorsHideyuki Koseki, Yusuke Nonaka
Life of this patent
Estimating the term…
Abstract
A disk array device that can detect the successful completion of data overwrite/update at high speed only by checking a UDT is provided. When a DIF is used as a verification code appended to data, check information that detects the successful completion of overwrite is defined in the UDT, in addition to address information that detects positional errors. Upon request of overwrite/update of data stored in a cache, a check bit of the data in the cache is changed to a value different from a check bit to be appended to new data by a host adapter. Then, data transfer is initiated. Upon completion of the data overwrite, the check bit is changed back to the original value, whereby it is possible to detect the successful completion of overwrite/update (FIG. 8).
Claims11
A storage device comprising:
- a cache memory configured to store data from a host computer;
- a host adapter coupled to the host computer;
- a processor configured to control the cache memory;
- and
- a disk unit;
- wherein when the host adapter receives a first write request with write data from the host computer, the write data not being written in the cache memory, the host adapter is configured to:
- add positional information of the write data in the disk unit and check information set as first data to the write data;
- write the write data with the positional information and the check information to the cache memory;
- and
- check whether the positional information written in the cache memory is correct;
- and
- wherein when the host adapter receives a second write request with update data to the write data in the cache memory,
- the processor is configured to change the check information of the write data in the cache memory from the first data to second data;
- and then
- the host adapter is configured to:
- add positional information of the update data in the disk unit, which positional information is the same as the positional information of the write data and check information set as the first data to the update data;
- overwrite the write data with the positional information and the check information set as the second data in the cache memory by the update data with the positional information and the check information set as the first data to the cache memory;
- and
- check whether the positional information written in the cache memory is correct and whether the check information is set as the first data.
A method for controlling a storage device comprising:
- when a host adapter receives a first write request with write data from a host computer, the write data not being written in a cache memory,
- adding, using the host adapter, positional information of the write data in a disk unit and check information set as first data to the write data;
- writing, using the host adapter, the write data with the positional information and the check information to the cache memory;
- and
- checking, using the host adapter, whether the positional information written in the cache memory is correct;
- and
- when the host adapter receives a second write request with update data to the write data in the cache memory;
- changing, using the host adapter, the check information of the write data in the cache memory from the first data to second data;
- then
- adding, using the host adapter, positional information of the update data in the disk unit, which position information is the same as the positional information of the write data, and check information set as the first data to the update data;
- overwriting, using at least one computer, the write data with the positional information and the check information set as the second data in the cache memory by the update data with the positional information and the check information set as the first data to the cache memory;
- and
- checking, using the host adapter, whether the positional information written in the cache memory is correct and whether the check information is set as the first data.
Dependencies are inferred from the claim text.