Patent ID: 7421446
Filing Date: 2008-09-02
Classification: G06F,Y10S

Abstract:
1. A method for allocating storage for a file, comprising: reserving a quantity of sequential physical storage for the file; selecting, in response to each call to allocate an available portion of the storage of the file, one of a plurality of allocation approaches based on a value of a file attribute associated with the file; establishing a plurality of allocation records for the file and assigning initial respective portions of the reserved quantity of storage with the allocation records, wherein for the value of the file attribute specifying a first of the allocation approaches, the initial respective portions increase in quantity from a first of the allocation records to a last of the allocation records, and for the value of the file attribute specifying a second of the allocation approaches, the initial respective portions have equal quantities; selecting for storage of data, in response to selection of the first allocation approach, a portion of storage of the file from one of the respective portions assigned to one of the allocation records, wherein the selecting under the first approach begins with the first allocation record and proceeds toward the last allocation record in seeking an available portion to allocate wherein physical storage is allocated based on maintaining sequentially allocated portions; selecting for storage of data, in response to selection of the second allocation approach, a portion of storage of the file from one of the respective portions assigned to one of the allocation records, wherein the selecting under the second approach begins with an allocation record other than the first allocation record in seeking an available portion to allocate wherein physical storage is allocated based on maintaining concurrent access to the file; and in response to an allocation record having no available portion of storage for the file, reassigning portions from one allocation record to another, wherein reassigning for the file attribute indicating the first approach reassigns portions from a next successive allocation record, and reassigning for the file attribute indicating the second approach balances respective portions assigned to the allocation records.