[TUHS] UNIX testing / error injection

[Theodore Tso via TUHS]

On Wed, Apr 15, 2026 at 06:31:01PM +0100, Sevan Janiyan via TUHS wrote:
> On 14/04/2026 21:40, Adam Koszek via TUHS wrote:
> > Were there any more examples of this?
> 
> File System eXerciser (aka fxr.c) by Avie Tevanian at NeXT.
> Covered in Avie Tevanian CHM oral history interview, can't remember which
> part though. There's 2 lengthy sessions. Good excuse to watch both? :)

Fsx[1] is still used to test file systems in Linux today[2].  It came
through xfstests from SGI, so it was used to test Irix file systems
before it came to Linux.  It's doesn't do error injectionm and in
general it runs on the system under test (SUT) so it's not an example
of something that tested the file system in userspace --- unless you
consider using a VMM such as qemu as "userspace testing".

[1] https://github.com/tytso/xfstests/blob/master/ltp/fsx.c
[2] https://github.com/tytso/xfstests-bld/blob/master/Documentation/what-is-xfstests.md

					- Ted