  Caching plays a crucial role in networking systems to reduce the load on the
network and is commonly employed by content delivery networks (CDNs) in order
to improve performance. One of the commonly used mechanisms, Least Recently
Used (LRU), works well for identical file sizes. However, for asymmetric file
sizes, the performance deteriorates. This paper proposes an adaptation to the
LRU strategy, called gLRU, where the file is sub-divided into equal-sized
chunks. In this strategy, a chunk of the newly requested file is added in the
cache, and a chunk of the least-recently-used file is removed from the cache.
Even though approximate analysis for the hit rate has been studied for LRU, the
analysis does not extend to gLRU since the metric of interest is no longer the
hit rate as the cache has partial files. This paper provides a novel
approximation analysis for this policy where the cache may have partial file
contents. The approximation approach is validated by simulations. Further, gLRU
outperforms the LRU strategy for a Zipf file popularity distribution and
censored Pareto file size distribution for the file download times. Video
streaming applications can further use the partial cache contents to help the
stall duration significantly, and the numerical results indicate significant
improvements (32\%) in stall duration using the gLRU strategy as compared to
the LRU strategy. Furthermore, the gLRU replacement policy compares favorably
to two other cache replacement policies when simulated on MSR Cambridge Traces
obtained from the SNIA IOTTA repository.
