1. A storage system comprising: a processor coupled to a memory; a plurality of vdisks, each vdisk containing a plurality of storage segments, each segment providing a specific class of service (COS) for storage different from the CoS for storage of the other segments; each vdisk storing one or more files with data and meta data distributed among its storage segments, each file's meta data including a search tree indexed by logical block number, each file described by a single inode, a first portion of a file's data is stored in a first segment, and a second portion of the file is stored in a second segment, a vdisk to hold a newly created file or directory is chosen from the plurality of vdisks based on a predetermined mapping into the plurality of vdisks.