"The petard filesystem is designed to produce only errors--but
you can stipulate what conditions generate the errors and what
those errors should be. That makes petardfs useful for system and
unit testing--for example, making sure that an application gives a
sane error message if it fails to open a file, or if there is a
read error at byte 5000 of a file.
"Petardfs uses Filesystem in Userspace (FUSE) to allow easy
setup without requiring a kernel recompile or new kernel modules.
In normal configuration you specify a 'base filesystem' and give a
mountpoint--for example, saying that /home/ben/foo is the base
filesystem and mounting the filesystem at