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Glamour is a file virtualization and data management solution that leverages open standards
(e.g., NFS) for file access. Glamour provides a common namespace so clients can see a consistent
view across a group of distributed, heterogeneous wide-area distributed fileservers. While Glamour
is not a globally distributed file system, it enables a set of loosely coupled file servers to
function as one. With Glamour the logical location of a file in the shared namespace is separate
from the physical location at a fileserver. This simplifies the user experience by presenting a
consistent filesystem view when traversing through files physically located on multiple
fileservers. Furthermore, Glamour supports smart data management by replicating sets of data at
custom granularities for both load balancing and failover. Glamour was made available as the
Network Data Access Facility (NDAF) offering on
AIX 5.3 and has been prototyped
on Linux.
As a first step towards building globally federated file services, Glamour used the NFSv4
protocol's referral mechanism to provide a common namespace across multiple file servers. This
initial scope was further extended to support multiple file access protocols such NFSv3 and CIFS
and multiple non-Glamour enabled platforms such as NAS filers. We have ongoing collaboration with
NetApp to define possible standards for interacting with NAS filers.
In any wide-area distributed federation, performance becomes a key issue. One technique for
improving performance is to support remote data caching. This enables clients to access the
remote data from a local server's cache without incurring WAN latencies. Glamour's remote data
cache is designed for both scalability and interoperability. For true scalability the cache
data needs to be stored persistently in a clustered filesystem and accessed in parallel from
the remote site while maintaining cache consistency. Ongoing work at research is exploring how
best to build such a caching system.
IBM Almaden Research - File Systems
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Glamour: A Wide-Area Filesystem Middleware Using NFSv4,
Renu Tewari, Jonathan M. Haswell, Manoj P. Naik, Steven M. Parkes, IBM Research Report, RJ10368, July 2005.
TAPER: Tiered Approach for Eliminating Redundancy in Replica Synchronization,
Navendu Jain, Mike Dahlin, and Renu Tewari, FAST '05, December 14-15, 2005.
Nache: Design and Implementation of a Caching Proxy for NFSv4,
Ajay Gulati, Manoj Naik, and Renu Tewari, FAST '07, February 13-16, 2007.
Glamour: An NFSv4-based File System Federation,
Jonathan M. Haswell, NAS Industry Conference, October 19, 2005.
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