Hi Ben,
Is there any safe (non-writing) Block test that I can try on my computer?
how about taking the following program as starting point?
https://github.com/genodelabs/genode/blob/master/repos/os/src/test/block_ben...
You will need to modify it to omit the second part where data is written to the block device. I think, the program is simple enough to provide a nice playground.
Regards Norman