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5. Related Work

5.1 Cyclic News File System

The Cyclic News File System (CNFS)[Fritchie97] stores articles in a few large files or in a raw block device, recycling their storage when reaching the end of the buffer. CNFS avoids most of the overhead of traditional FFS-like[McKusick84] file systems, because it reduces the need for many synchronous meta-data updates. CNFS reports an order of magnitude reduction in disk activity.

CNFS requires substantial modifications to INN 1.7, and is planned as part of INN 2.0. INN 2.0 in still under development and will take a long time to to become stable along with CNFS, and even longer to deploy throughout the Internet. Moreover, transition from the traditional storage method to CNFS will not be trivial. This underscores our point that any work that makes significant modifications to large news software packages will take a lot of time to become widely distributed.

5.2 XFS

XFS[Sweeney96] is Silicon Graphics' new file system for the IRIX operating system. It supports large file systems, a large number of files, large files, and very large directories. XFS uses B+ trees to store data and meta-data on disk, avoiding the traditional linear directory structure, and achieving good performance improvements over IRIX's older file system, EFS.

XFS comes only with IRIX and is not likely to be available for other operating systems. Since the requirements of news systems change often due to increasing resource demands, news administrators usually opt for less expensive off-the-shelf hardware that can be upgraded easily and inexpensively -- mostly high-end PCs; they are not likely to purchase a more expensive SGI system.

5.3 reiserfs

Reiserfs6 is a file system for Linux that uses balanced trees to optimize performance and space utilization for small and large files alike. By balancing files and their names, directories are packed more efficiently resulting in faster access.

Reiserfs is free but available only for Linux. It is a native disk-based file system and as such is very difficult to port to other operating systems. It is a complex and large piece of software that will take time to become stable and available for production use. (We have tried to test reiserfs but the kernel module crashed after creating some 50,000 files in one directory.)

next up previous
Next: 6. Conclusions Up: Usenetfs: A Stackable File Previous: 4. Evaluation
Erez Zadok