Patent
1995-06-07
1997-11-04
Black, Thomas G.
395613, 395614, 395615, G06F 1730
Patent
active
056849869
ABSTRACT:
An embedded directory record and method are provided for maintaining directory information for compressed data on a direct access storage device (DASD). The embedded directory record includes a plurality of page entries, a plurality of exception region entries and a plurality of compression group statistics. Each page entry includes an allocated page length value and a number of used sectors value in the allocated page. The exception region entries include a page index and a bit map used for identifying exception sectors used. The compression group statistics include a total count of allocated sectors, a total count of the used sectors; and a total count of written pages. A starting page address for a requested page is identified beginning at a start of the page entries by summing the allocated page length values for each page up to the requested page to identify an offset value and combining the offset value with a predetermined logical block address. Reading and writing directory information utilize skip read and skip write operations.
REFERENCES:
patent: 4247892 (1981-01-01), Lawrence
patent: 4353653 (1982-10-01), Zimmerman
patent: 4403288 (1983-09-01), Christian et al.
patent: 4533995 (1985-08-01), Christian et al.
patent: 4775969 (1988-10-01), Osterlund
patent: 4797741 (1989-01-01), Sato et al.
patent: 5031218 (1991-07-01), Galand et al.
patent: 5034914 (1991-07-01), Osterlund
patent: 5247646 (1993-09-01), Osterlund et al.
patent: 5465167 (1995-11-01), Cooper et al.
patent: 5553286 (1996-09-01), Lee
Brodie et al. Pat. Appln. S.N. 08/343,316 filed Nov. 22, 1994--Method and Means for Managing Linear Mapped Address Spaces Storing Compressed Data at the Storage Subsystem Control Unit or Device Level.
Moertl Daniel Frank
Stevens John Douglas
Van Grinsven Gene Steven
Walk Bruce Marshall
Black Thomas G.
Coby Frantz
International Business Machines - Corporation
Pennington Joan
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