The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 30, 2003
Filed:
Jan. 07, 2000
Henk Vandenbergh, Lafayette, CO (US);
Michael Steven Milillo, Louisville, CO (US);
Gregory William Peterson, Lyons, CO (US);
Storage Technology Corporation, Louisville, CO (US);
Abstract
Each time a track is referenced, a value representing the last referenced age is entered for a track entry in a last referenced age table (LRAT). The last referenced age table is indexed by track. A second table, an age frequency table (AFT), counts all segments in use in each reference age. The AFT is indexed by the reference age of the tracks. When a track is referenced, the number of segments used for the track is added to a segment count associated with the last referenced age of the track. The segment count tallies the total number of segments in use for the reference age for all tracks referenced to that age. The number of segments used for the previous last referenced age of the track is subtracted from the segment count associated with the previous last referenced age in the AFT. When free_space is needed, tracks are discarded from the LRAT by reference age, the oldest first. The range of ages to be discarded in the LRAT is calculated in the AFT by counting the total amount of segments used by each reference age until the total number of segments needed is realized. Counting is started at the AFT entry with the oldest reference age. The reference age of the last counted entry in the AFT is the discard age. The LRAT is scanned for reference ages between the old age, and those reference ages are discarded.