Free Software Linux

Daniel Phillips noted that his new Tux3 versioning filesystem is now operating like a filesystem, "the last burst of checkins has brought Tux3 to the point where it undeniably acts like a filesystem: one can write files, go away, come back later and read those files by name. We can see some of the hoped for attractiveness starting to emerge: Tux3 clearly does scale from the very small to the very big at the same time. We have our Exabyte file with 4K blocksize and we can also create 64 Petabyte files using 256 byte blocks." He went on to discuss some of the remaining features yet to be implemented, including atomic commits, versioning, coalesce on delete, a version of the filesystem written in the kernel, extents, locking, and extended attributes.

"It is about time to take a step back and describe what I have been implementing," began Daniel Phillips, referring to his new Tux3 filesystem. He provided a simple ASCII diagram that detailed the filesystem's hierarchical structure, describing each of the elements. About one he noted, "the volume table is a new addition not central to the goals of Tux3, but a nice feature to have given that it comes nearly for free. One Tux3 volume can have an arbitrary number of separate filesystems tucked inside it, indexed by a simple integer parameter at mount time. People say they like this idea and it imposes no significant complexity, so it goes in." Daniel continued:

"The big advantage Hammer has over Tux3 is, it is up and running and released in the Dragonfly distro," began Daniel Phillips, offering a comparison between the two filesystem. He continued, "the biggest disadvantage is, it runs on BSD, not Linux, and it so heavily implements functionality that is provided by the VFS and block layer in Linux that a port would be far from trivial. It will likely happen eventually, but probably in about the same timeframe that we can get Tux3 up and stable." This led into a lengthy and interesting technical discussion between Daniel and HAMMER author Matthew Dillon, comparing the design of the two filesystems.