UFS: The Root of All Evil 279 Unfortunately, the whole underlying design of the Unix file system—direc- tories that are virtually content free, inodes that lack filenames, and files with their contents spread across the horizion—places an ultimate limit on how efficient any POSIX-compliant file system can ever be. Researchers experimenting with Sprite and other file systems report performance that is 50% to 80% faster than UFS, FFS, or any other file system that implements the Unix standard. Because these file systems don’t, they’ll likely stay in the research lab. Date: Tue, 7 May 1991 10:22:23 PDT From: Stanley’s Tool Works lanning@parc.xerox.com Subject: How do you spell “efficient?” To: UNIX-HATERS Consider that Unix was built on the idea of processing files. Consider that Unix weenies spend an inordinate amount of time micro-opti- mizing code. Consider how they rant and rave at the mere mention of inefficient tools like a garbage collector. Then consider this, from an announcement of a recent talk here: …We have implemented a prototype log-structured file system called Sprite LFS it outperforms current Unix file systems by an order of magnitude for small-file writes while matching or exceeding Unix performance for reads and large writes. Even when the overhead for cleaning is included, Sprite LFS can use 70% of the disk bandwidth for writing, whereas Unix file systems typically can use only 5-10%. —smL So why do people believe that the Unix file system is high performance? Because Berkeley named their file system “The Fast File System.” Well, it was faster than the original file system that Thompson and Ritchie had written.

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