Recording apparatus and method for an arrayed recording apparatus

An arrayed recording apparatus comprising:

• a plurality of recording devices each of which rotates, has a write area with a plurality of blocks, and store data in a block unit, wherein at least one of the recording devices includes a temporary write area separate from a write area, and wherein the recording devices include at least one redundant device for recording the redundant data,
• an array controller for accessing data and redundant data recorded in the blocks of the plurality of recording devices as a group, said array controller including:
• temporary write means for writing data into a temporary write area of one of the recording devices without calculating redundant data,
• memory means, for storing a data position in a memory where the temporary write means writes data, and
• re-write means for reading necessary data for calculating redundant data in a group wherein data written by the temporary write means belongs according to the data position stored by the memory means, calculating redundant data based on the data read, and recording the redundant data into the redundant device.

An arrayed recording apparatus comprising:

• a plurality of recording devices each of which rotates, has a write area with a plurality of blocks, and stores data in a block unit, wherein each of the recording devices has a cache memory,
• an array controller for accessing data and redundant data recorded in the blocks of the plurality of recording devices as a group, wherein said array controller includes temporary write means for writing data into one of the recording devices without calculating redundant data,
• memory means, for storing in a memory a data position where temporary write means writes data, and
• re-write means for requesting a prefetch of necessary data for calculating the redundant data to the cache memories in recording devices which data were not written into by the temporary write means, reading data from the cache memories in the recording devices according to the data position stored by the memory means at the end of the prefetch of data in the cache memories, calculating the redundant data according to data read, and recording the redundant data in a redundant device.

An arrayed recording apparatus comprising:

• a plurality of recording devices each of which has a write area with a plurality of blocks, and stores data in a block unit, an array controller for accessing data and redundant data recorded in the blocks of the plurality of recording devices as a group, the arrayed controller including
• initialize means for dividing the write area into a plurality of divided areas so as to define corresponding blocks in the other divided areas to a block in one divided area, and initializing each of the divided areas;
• a memory for storing initialize information which indicates whether the block is initialized by the initialize means and for storing divided area information which indicates a divided area when data are recorded in the corresponding block of the other divided area, for each of blocks;
• write means, for referring to the initialize information for blocks in the group stored in the memory, for finding all blocks of a group which indicate the initialized status, and for writing data in the blocks of the group found if all the blocks in the group indicate the initialized status;
• and
• memory update means for updating initialize information to indicate that blocks are not initialized status for blocks where data are written by the write means, and registering divided area information with the divided area to indicate that data are recorded in the corresponding blocks in the divided area if data are written in the corresponding blocks in other divided area.

A recording apparatus which is accessed data in a first size unit from a host machine and accesses data in a second size unit, which is smaller than the first size, in a recording device, comprising:

• a cache memory for storing data read from the recording device;
• interface means for input;ting and outputting data in the first size unit from and to the host machine using the cache memory;
• compare means for comparing data of the first size unit according to a write command with data stored in the cache memory, per the second size unit;
• update means for updating data of the recording device per the second size unit based on the comparing result of the compare means.

A recording method for an arrayed recording apparatus having a plurality of recording devices for recording data in a write area, at least one of the plurality of recording devices including a temporary write area separate from the write area, and an array controller for controlling accesses to the recording devices, said method comprising the steps of:

• (a) temporarily writing data in the temporary write area of one of the recording devices without calculating redundant data;
• (b) storing a location of data written by the temporarily writing step;
• (c) reading data from the stored location;
• (d) calculating redundant data based on the data read by the reading step;
• and
• (e) re-writing the redundant data calculated by the calculating step to a redundant device.

A recording method for an arrayed recording apparatus having a plurality of recording devices for recording data in a write area, and an array controller for controlling accesses to the recording devices, said method comprising the steps of:

• (a) temporarily writing data through a cache memory in a specified recording device without calculating redundant data;
• (b) prefetching data needed for calculating redundant data into cache memories from the other recording devices which are not specified for writing data;
• (c) calculating the redundant data according to the data in the cache memories;
• and
• (d) writing the redundant data to one of the recording devices.

A recording method for an arrayed recording apparatus having a plurality of recording devices for recording data in a write area, and an array controller for controlling accesses to the recording devices, said method comprising the steps of:

• (a) dividing the write area into a plurality of divided areas so as to provided corresponding redundant groups among the divided areas;
• (b) initializing the divided areas;
• (c) searching the corresponding redundant groups in the divided areas to locate a redundant group which is initialized;
• (d) writing data in the initialized redundant group found by the searching step;
• and
• (e) storing the divided area where data are written by the writing step in the original redundant group.

A recording method for a recording apparatus which receives data in a first size unit from a machine into a buffer and accesses data in a second size unit in a recording device, comprising the steps of:

• (a) reading data in the second size unit a plurality of times into the buffer from the recording device;
• (b) transferring data in the first size unit to said machine;
• (c) receiving updated data in the first size unit from the machine;
• (d) comparing said updated data and data in the buffer per the second size unit;
• and
• (e) updating data per the second size unit in the recording drive if the comparing result per the second size unit by the comparing step shows a difference.