STL mapping table management method based on Ondemand algorithm

Abstract

The invention discloses an STL mapping table management method based on an Ondemand algorithm. When reading operation is needed, a cache table LPT_stack is inquired through LBA, if a corresponding mapping table item exists in the cache table, corresponding PBA is acquired, and after an actual physical block number is acquired by inquiring BMT, data is directly read; if the corresponding mapping item is not found in the cache table, a mapping table in a disk is sought, and all mapping table items of a sector where the mapping table item is located are put into a cache. When writing operation is needed, LBN where the LBA is located is calculated, a BMT table is sought with the LBN as an index, and then PBN is acquired; if no PBN exists, a data strip is directly distributed, or otherwise, whether a corresponding data strip has space for writing of a data block or not is checked, if yes, writing is directly carried out, and if not, erasing is carried out on the data strip, invalid data blocks are released, and data is written into the corresponding strip; after the data is written in, the corresponding mapping table item is modified.

Description

technical field [0001] The invention belongs to the field of computers, and more specifically relates to a method for managing an STL (shingledmagnetic record translation layer) mapping table based on an Ondemand algorithm. Background technique [0002] For SMR (Shingled Magnetic Recording) disks that use disk block mapping table technology to manage the mapping relationship between logic and physical space, each time the operating system applies for a read or write operation from the disk, it needs to query the mapping table to map the logical disk block number to the physical space. Disk number. [0003] The existing technology directly imports the mapping table into the memory, resulting in low space and time performance. The specific limitations include the following two aspects: (1) The data exchange between the memory and the disk is slow, and the mapping table is directly imported from the disk into the memory, or the The memory data is written to the disk, and the d...

AI Technical Summary

Problems solved by technology

Import the mapping table into the memory at one time, seriously affecting the utilization of memory space and the overall performance of the computer

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