The VxFS filesystem from VERITAS is an example of a UNIX filesystem that not only offers a broad range of advanced functionality, such as extent based allocation, intent logging, snapshoting, but also has on-disk formats with various differences between the versions and ports.

FreeVxFS is a freely available implementation of the VxFS filesystem format for Linux, implemented only by looking at the very rarely available public documentation and reverse engineering the SCO UnixWare version of the commercially available VXFS driver.

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