A storage system comprises a plurality of vdisks, with each vdisk containing a plurality of storage segments, and each segment providing a specific class of service (CoS). Each vdisk stores files with data and meta data distributed among its storage segments. A storage system comprises a memory having multiple classes of service. The system comprises an interface for storing a file as blocks of data associated with a class of service in the memory. The interface chooses the class of service for a block on a block by block basis. A file system for storing a file comprises a plurality of vdisks, with each vdisk having a plurality of inodes. Each inode of each vdisk stores data on one or more segments, with each segment having a different class of service. The system comprises a controller which stores data of a file in an inode of a vdisk, in one or more segments of that vdisk. A file system for storing a file comprises a plurality of vdisks, and each vdisk having a plurality of inodes. The system comprises a controller including a plurality of processors, with each processor serving one or more of the vdisks. A file system for storing comprises a plurality of vdisks, with each vdisk having a plurality of inodes, a plurality of inodes of at least one vdisk storing data on a plurality of segments, each segment having a different class of service. The system comprises a controller which stores data of the file in one or more segments of one vdisk. A method for storing a file.