System and method for supporting file and block access to storage object on a storage appliance

A technique enables application data stored on storage devices of a storage system to be accessible by a client as either a file or logical unit number (lun). The storage system is illustratively embodied as a multi-protocol storage appliance having a storage operating system that implements a file system. The file system logically organizes the application data as a virtual disk (vdisk) comprising a plurality of inodes including a prefix stream inode, a lun inode (storing the application data) and a suffix stream inode. The prefix and suffix stream inodes allow the vdisk to be shared over a block-based protocol or a file-based protocol by enabling apportionment of client operating system dependent storage device contents from application data contents of the vdisk.