Patent attributes
A computer accessible medium comprises instructions which, when executed, receive a request to allocate one or more blocks for a file. At least one allocation policy is assigned to the file, wherein the allocation policy specifies one or more storage units on which the blocks are to be allocated. Additionally, if more than one storage unit is specified, the allocation policy includes a control indication indicating a mechanism for selecting among the storage units. The instructions, when executed, may also allocate blocks according to the allocation policy. In another implementation, a computer accessible medium comprises instructions which, when executed receive a request to allocate one or more blocks for a file in a filesystem and allocate blocks according to an allocation policy. Allocation policies are specifiable at two or more levels of granularity in the filesystem.