CITI is responsible for developing a reference implementation of NFSv4 that is included in the open source Linux operating system and is being incorporated into Novell and Red Hat Linux distributions.
CITI is engineering NFSv4 for use as a universal standard for fast and secure access to stored data, whether across a wide area network (WAN) or within a single location.
"PolyServe is a critical partner in CITI's development of the NFSv4 implementation for Linux," said Peter Honeyman, scientific director of CITI.
NFSv4 was the logical starting point for DAFS because it is an open standard, has good failure recovery characteristics, ACL support, high-performance locking, and accommodates both Unix- and Windows-style access mechanisms.
DAFS chaining provides the benefits of NFSv4 COMPOUND in a low-latency environment.
DAFS semantic improvements to NFSv4 focus on environments where clusters of application servers have shared access to pools of file storage.
Although NFSv4 introduced major improvements in locking, NFSv4 clients cannot detect that a file lock has been released abnormally, possibly causing the underlying file data to be corrupted.
The Direct Access File System protocol is based on NFSv4, but it reorganizes how requests are presented to the transport protocol for transmission.