Managing RAID on Linux

ReiserFS

ReiserFS is the brainchild of Hans Reiser, although today, a large cavalcade of developers is involved in its production. ReiserFS was the first journaling filesystem developed for Linux and has held its own remarkably well, considering that IBM and SGI have contributed impressive alternatives (the JFS and XFS filesystems, respectively).

Reiser began the ReiserFS project with an untraditional design that uses balanced trees^[5] to manage and organize the filesystem, instead of a traditional linked list approach. Balanced trees have been used for quite some time in database architecture, but various disappointing attempts to create balanced-tree filesystems have led many in the operating system community to believe they are not suited to that purpose. Reiser, on the other hand, maintains that a proper implementation will eventually result in a better-performing and more reliable filesystem. While some other filesystems that have implemented the balanced tree algorithm used the tree to manage only metadata, ReiserFS stores both files and filesystem metadata in the balanced tree structure.

The ReiserFS design approach works very well for small files and for filesystem metaoperations, such as deletion. While ReiserFS used to struggle with performance on larger files, those issues have now been all but resolved, and some improved code for large files will appear in the 2.4.20 kernel, as well as in future development kernels. Performance continues to be a priority for Hans Reiser, ...