A set of data management services is proposed to provide control and configuration of application-tailored data sessions using Grid Virtual File System (GVFS), GridFTP, and Secure Copy (SCP). GVFS employs proxies to virtualize Network File System (NFS) sessions via interception and modification of remote procedure calls. In our data management architecture, a File System Service (FSS) runs on every client and server and controls the local file system proxies; a Data Scheduler Service (DSS) provides centralized scheduling and control of data sessions through interactions with the FSSs; and a Data Replication Service (DRS) manages datasets and their replicas for fault tolerance and load balancing. Using these services, GVFS-based data sessions can be dynamically created on a per-application basis, and application-tailored customizations can be applied, including: the selection of block-based or whole-file based data transfer, the configuration of cache parameters and consistency protocols, the use of copy-on-write based check-pointing and replication-based failover, and the configuration of security mechanisms. These services support the interoperability with other grid middleware based on WSRF standards, and also employ the web service security standards to provide secure interactions and grid authentication and access control.