Method and apparatus for file storage allocation for secondary storage using large and small file blocks

摘要

A method and apparatus for file storage allocation for secondary storage systems for allocating storage space for both small and large files in the same file system that dynamically utilizes at least two different sizes of logical storage allocation units to organize files stored on one or more physical storage devices. A first, smaller logical allocation unit is used to allocate space for the beginning of files until the size of the file passes a predefined maximum small allocation unit size. Beyond the predefined maximum small allocation unit size for a file, a second, larger logical allocation unit is used to allocate the remaining space necessary to store the file. In the preferred embodiment, small allocation units of 1K and large allocation units of 16K are used to map files directly and indirectly to the physical storage devices in a secondary file storage system. Such that the addressable storage capacity in a secondary file storage system is maximized while the amount of unused storage space is minimized.