Management of orphan tracks
AssigneeEMC Corporation
InventorsAviram Cohen, Ishai Kedem
Life of this patent
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Abstract
The meta-data pattern for records in an orphan track is not readily compressible into a form suitable for maintaining in memory. A method is provided for periodically attempting to compress meta-data from orphan tracks as newly compressible meta-data patterns are made available. The method includes specifying a compressed representation for a first meta-data pattern and determining a second meta-data pattern formed by the meta-data associated with the orphan track. If the second meta-data pattern is consistent with the first meta-data pattern, a compressed representation of the second meta-data pattern is generated and maintained in memory. In an optional feature, meta-data that could not be compressed is collected and periodically transmitted to a data-analysis node for analysis.
Claims26
A method for reducing latency associated with accessing a desired record from an orphan track on a mass-storage device, said orphan track including a plurality of records, each having associated meta-data, said method comprising:
- specifying a compressed representation for a first meta-data pattern;
- determining a second meta-data pattern formed by said meta-data associated with said plurality of records of said orphan track;
- and
- if said second meta-data pattern is consistent with said first meta-data pattern,
- generating a compressed representation of said second meta-data pattern, and
- maintaining a copy of said compressed representation in a memory element.
A data-storage system comprising:
- a mass-storage device having an orphan track with records formatted according to a first meta-data pattern;
- a memory element having a first table for storage of compressed representations of meta-data patterns for tracks on said mass-storage device;
- and
- an orphan-scanning process for generating a compressed representation of said first meta-data pattern and incorporating said compressed representation into said first table.
A method for reducing the number of orphan tracks on a mass-storage device, said method comprising:
- identifying an orphan track on said mass-storage device, said orphan track having a plurality of records formatted according to a first meta-data pattern;
- attempting to generate a compressed representation of said first meta-data pattern;
- and
- if said attempt is successful, incorporating said compressed representation of said first meta-data pattern into a memory element for storage of meta-data patterns associated with each track on said mass-storage device.
A computer-readable medium having encoded thereon software for reducing the number of orphan tracks on a mass-storage device, said software comprising instructions for:
- identifying an orphan track on said mass-storage device, said orphan track having a plurality of records formatted according to a first meta-data pattern;
- attempting to generate a compressed representation of said first meta-data pattern;
- and
- if said attempt is successful, incorporating said compressed representation of said first meta-data pattern into a memory element for storage of meta-data patterns associated with each track on said mass-storage device.
A data-storage system comprising:
- a mass-storage device having an orphan track with records formatted according to a first meta-data pattern;
- a memory element for storage of a table of meta-data patterns obtained from orphan tracks on said mass-storage device;
- and
- an orphan-scanning process for retrieving said first meta-data pattern and storing said first meta-data pattern in said table.
Dependencies are inferred from the claim text.