American Megatrends Assigned Patent

American
Megatrends, Norcross, GAn has been assigned a patent (8,370,597)
developed by four co-inventors for a "data migration between
multiple tiers in a storage system using age and frequency
statistics."

The co-inventors are Paresh Chatterjee,
Fremont, CA, Ajit Narayanan, Chennai, India, Loganathan Ranganathan,
Fremont, CA, and Sharon Enoch, Newark, CA.

The abstract of the patent published by
the U.S. Patent and Trademark Office states: "Technologies
are described for implementing a migration mechanism in a storage
system containing multiple tiers of storage with each tier having
different cost and performance parameters. Access statistics can be
collected for each territory, or storage entity, within the storage
system. Data that is accessed more frequently can be migrated toward
higher performance storage tiers while data that is accessed less
frequently can be migrated towards lower performance storage tiers.
The placement of data may be governed first by the promotion of
territories with higher access frequency to higher tiers. Secondly,
data migration may be governed by demoting territories to lower tiers
to create room for the promotion of more eligible territories from
the next lower tier. In instances where space is not available on the
next lower tier, further demotion may take place to an even lower
tier in order to make space for the first demotion."

The patent application was filed on
April 11, 2008 (12/101,236)