Buffering data in a hierarchical data storage environment
First Claim
1. A method of buffering first requested data from a first file in a hierarchical data storage system including memory, a primary storage device, and a secondary storage device, the secondary storage device including a first logical data unit having a logical unit size, the method comprising:
- allocating data buffers in the memory including a first data buffer;
receiving a first no recall data request associated with a first file-based identifier to the first requested data, if the first requested data is not stored on the primary storage device;
retrieving the first requested data from the first logical data unit of the secondary storage device, responsive to the first no recall data request;
selecting the first data buffer based on a relative availability status of the first data buffer;
storing the first logical data unit in the first data buffer;
associating the first data buffer with the first file-based identifier; and
organizing the first data buffer among the data buffers based on the first file-based identifier.
1 Assignment
0 Petitions
Accused Products
Abstract
A system, a method, and program products for buffering data from a file in a hierarchical data storage system allocates data buffers and buffer management structures in memory to optimize performance of no recall requests. Buffer management structures, such as buffer headers and hash queue headers, are used to optimize performance of insert, search, and data buffer reuse operations. Buffer headers are managed in a least-recently-used queue in accordance with a relative availability status. Buffer headers are also organized in hash queue structures in accordance with file-based identifiers to facilitate searching for requested data in the buffers. Data buffers can be used to buffer different data blocks within the same file and can be recycled to buffer data from other data blocks and other files from the secondary storage device. Data in a data block may be reread by the requesting process or by other processes as long as the requested data remains valid. Lock fields are used to coordinate multi-thread and multi-user accesses.
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Citations
23 Claims
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1. A method of buffering first requested data from a first file in a hierarchical data storage system including memory, a primary storage device, and a secondary storage device, the secondary storage device including a first logical data unit having a logical unit size, the method comprising:
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allocating data buffers in the memory including a first data buffer;
receiving a first no recall data request associated with a first file-based identifier to the first requested data, if the first requested data is not stored on the primary storage device;
retrieving the first requested data from the first logical data unit of the secondary storage device, responsive to the first no recall data request;
selecting the first data buffer based on a relative availability status of the first data buffer;
storing the first logical data unit in the first data buffer;
associating the first data buffer with the first file-based identifier; and
organizing the first data buffer among the data buffers based on the first file-based identifier. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A computer program storage medium readable by a computing system and encoding a computer program for executing a computer process buffering requested data from a file in a hierarchical data storage system including memory, a primary storage device, and a secondary storage device, the secondary storage device including a logical data unit having a logical unit size, the computer program comprising instructions for:
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retrieving the requested data from the logical data unit of the secondary storage device, responsive to a no recall data request associated with a file-base identifier to the requested data;
selecting the data buffer based on a relative availability status of the data buffer;
storing the logical data unit in a data buffer allocated in memory;
associating the data buffer with the file-based identifier; and
organizing the data buffer among the data buffers based on the file-based identifier.
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18. A system for buffering first requested data in a hierarchical data storage system including memory, a primary storage device, and a secondary storage device, the secondary storage device including a first logical data unit and a second logical unit, the system comprising:
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a pool of data buffers allocated in memory including a first data buffer;
a pool of buffer headers allocated in memory including a first buffer header, each buffer header being associated with one of the data buffers and including a search key field;
a request processing module receiving a first no recall data request associated with a first file-based identifier to the first requested data;
a retrieval module retrieving the first requested data from the first logical data unit of the secondary storage device;
a selection module selecting the first buffer header being associated with the first data buffer based on a relative availability status of each data buffer and loading the first file-based identifier in the search key field of the first buffer header; and
a buffer management module manipulating the buffer headers based on values in the search key fields. - View Dependent Claims (19, 20, 21)
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22. A computer data signal embodied in a carrier wave by a computing system and encoding a computer program for executing a computer process for buffering requested data from a file in a hierarchical data storage system including memory, a primary storage device, and a secondary storage device, the secondary storage device including a logical data unit having a logical unit size, the computer program comprising instructions for:
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retrieving the requested data from the logical data unit of the secondary storage device, responsive to a no recall data request associated with a file-base identifier to the requested data;
storing the requested data from the logical data unit in a selected data buffer allocated in memory;
associating the selected data buffer with the file-based identifier;
organizing the selected data buffer among the data buffers based on the file-based identifier; and
providing the requested data to service the no recall request. - View Dependent Claims (23)
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Specification