Mostly contiguous file allocation technique involving file extension
AssigneeModular Computer Systems, Inc.
InventorJoseph A. Korty
Life of this patent
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AssigneeModular Computer Systems, Inc.
InventorJoseph A. Korty
Estimating the term…
A method for selecting the sizes and the ordering of the extents used to construct a file, a segment, or a virtual space of a computer system (file). The general method is defined to be any function, applied to this purpose, that, in general, attaches larger extents to the larger file addresses, and for which the selection of extent sizes is determined only by the address an extent is to reside at in the file, plus any tuning parameters. The method results in files which are mostly contiguous, and that stay mostly contiguous, irrespective of any growth or shrinkage the file may be subjected to during its lifetime. High contiguity improves performance by permitting a compact file representation, and, for disc files, improves performance by permitting larger blocks of data to be moved to or from the disc device, and by minimizing head seeks. The repeat factor, along with the doubling of extent size each time the repeat factor expires, is an important innovation that greatly reduces the internal and external fragmentation normally associated with extent based systems.
A file extension method for data processing files for selecting the sizes and ordering of the extents of a file, each extent including at least one block, wherein the size of an extent starting at a certain file address is an increasing function only of said file address and wherein all extents of the same size are adjacent to each other in the file, the extents being stored at arbitrary locations in a storage device, whereby files are kept contiguous or nearly contiguous as each extent has at least as many blocks as the extent immediately preceeding it.
A method for storing an extendable data processing file having a series of blocks, comprising:
Dependencies are inferred from the claim text.