When kernel functionality is desired in userspace, the common approach is to reimplement it for userspace interfaces. We show that use of existing kernel file systems in userspace programs is possible without modifying the kernel file system code base. Two different operating modes are explored: 1) a transparent mode, in which the file system is mounted in the typical fashion by using the kerne...

In this paper we present our ongoing work on the Pegasus File System (PFS), a distributed and customizable file system that can be used for off-line file system experiments and on-line file system storage. PFS is best described as an object-oriented component library from which either a true file system or a file-system simulator can be constructed. Each of the components in the library is easi...

In this paper, we have made an attempt to take a look under the hood of Spotlight and understand some of the following questions amongst others: • How well-integrated is Spotlight with the file system? • How reliable is the interface between Spotlight and the file system? • Is live update a myth or a reality under heavy file system activity? Based on our experiments, it seems that Spotlight is ...

A log structured file system (LFS) [1] writes all the file system data sequentially in a log-like structure. A log consists of a series of segments where each segment contains both data and inode blocks. Traditional file systems like ext2 usually write inode blocks at a fixed place on the disk, causing overhead due to disk seeks. A log structured file system gathers a segment worth of data in m...