The Cyclic News Filesystem: Getting INN To Do More With Less

When Usenet News servers were first implemented, the design principle of storing each Usenet article in a separate file appeared to be sound. However, the number of Usenet News articles posted per day has grown phenomenally in the past decade and shows no sign of abating. To stay ahead of the growth curve, Usenet administrators have been forced to buy faster machines, more RAM, and many more disk drives. Many of the performance limitations are caused by interactions with the underlying OS's filesystem, which is usually a Berkeley Fast Filesystem (FFS) derivative.

The Cyclic News Filesystem (CNFS) was designed to avoid most of FFS's major problems when used with INN: synchronous file linking/unlinking and sequential scanning of directory files. Articles are stored within a relative handful of large files, either as regular files on top of a standard filesystem or as block disk devices. Articles are stored sequentially within each file, resuming at the beginning of the file when the end is reached. Disk activity is reduced by an order of magnitude.