Following the recent announcement that UBIFS is nearly production ready, it was asked how UBIFS compares to LogFS. LogFS author Jörn Engel suggested, "both share similar design goals. Biggest difference is that ubifs works on top of ubi and depends on ubi support, while logfs works on plain mtd (or block devices) and does everything itself. Code size difference is huge. Ubi weighs some 11kloc, ubifs some 30, logfs some 8." He continued:
"Ubi scales linearly, as it does a large scan at init time. It is still reasonably fast, as it reads just a few bytes worth of header per block. Logfs mounts in O(1) but will currently become mindbogglingly slow when the filesystem nears 100% full and write are purely random. Not that any other flash filesystem would perform well under these conditions - it is the known worst case scenario."
Artem Bityutskiy replied, "I personally refuse to compare a finished FS with handles all the crucial flash features to a non-finished FS. It just makes no sense. LogFS was talked about back 2005 in Linux Kongress, but is not finished yet. Let's talk about it when it is production ready."