Method and system for compression of files for storage and operation on compressed files
AssigneeInternational Business Machines Corporation
InventorsJonathan AMIT, Noah AMIT, Nadav KEDEM
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Abstract
Methods and systems for creating, reading, and writing compressed data for use with a block mode access storage. The compressed data are packed into a plurality of compressed units and stored in a storage logical unit (LU). One or more corresponding compressed units may be read and/or updated with no need of restoring the entire storage logical unit while maintaining a de-fragmented structure of the LU.
Claims32
For use with a block mode access storage protocol, a method of creating compressed data for storage in at least one storage logical unit, said method comprising:
- a) creating in respect to at least one storage logical unit a corresponding virtual logical unit accessible by said block mode access protocol and configured to virtually accommodate raw data, wherein a size of the virtual logical unit corresponds to an estimated size of raw data which, being compressed, would substantially amount to a size of the storage logical unit;
- b) segmenting the virtual logical unit into one or more virtual storage portions constituting clusters;
- c) compressing the raw data accommodated in a cluster and thereby generating compressed data to be stored in a respective compressed section Within the storage logical unit;
- d) facilitating mapping between the compressed data stored in the compressed section and their virtual accommodation at the virtual logical unit.
For use with a block mode access storage protocol, a method of reading raw data stored as compressed data in at least one storage logical unit, wherein said compressed data are packed into one or more compressed sections corresponding to fixed-size portions of raw data constituting clusters virtually accommodated in a virtual logical unit, the method comprising:
- a) determining a first cluster to be read;
- b) determining a serial number of a corresponding compressed section;
- and
- c) facilitating restoring the data corresponding to said cluster.
For use with a block mode access storage protocol, a method of writing data at a given range to data stored as compressed data in at least one storage logical unit, Wherein said compressed data are packed into one or more compressed sections corresponding to fixed-size portions of raw data constituting clusters virtually accommodated in a virtual logical unit, the method comprising:
- a) determining first cluster to be updated thereby constituting the original cluster;
- b) determining a serial number of corresponding compressed section;
- c) facilitating restoring the data corresponding to said original cluster;
- d) calculating an offset of the updating data within said cluster and facilitating the update at the given data range;
- e) compressing the updated cluster into an updated compressed section;
- and
- f) facilitating overwriting said original compressed section with updated compressed section.
Dependencies are inferred from the claim text.