Simulating I/O errors [was: assume, assert, enforce, @safe]

[H. S. Teoh via Digitalmars-d]

On Fri, Aug 01, 2014 at 11:18:47AM -0400, Assaf Gordon via Digitalmars-d wrote:
> Sorry to hijack the thread, but:
> 
> On 07/31/2014 09:27 PM, Walter Bright via Digitalmars-d wrote:
> >
> >If you're brave and want to have some fun, fill up your hard disk so
> >it is nearly full. Now run your favorite programs that read and write
> >files. Sit back and watch the crazy results (far too many programs
> >assume that writes succeed). Operating systems also behave
> >erratically in this scenario, hence the 'brave' suggestion.
> >
> 
> If anyone is interested in simulating I/O errors and nearly-full file
> system on Linux, I can suggest the following scripts:
>  http://git.savannah.gnu.org/cgit/datamash.git/tree/build-aux/create_corrupted_file_system.sh
>  http://git.savannah.gnu.org/cgit/datamash.git/tree/build-aux/create_small_file_system.sh
> 
> The scripts create two ext3 images which can be mounted, and simulate
> I/O errors.
> One simulate file system with corrupted files (so "open" and the first
> "read" will succeed, but later "read" will fail with EIO),
> and the other simulate a tiny filesystem, so that the first few
> "writes" will succeed, but "write" of >40KB will fail with ENOSPC.
> 
> The scripts themselves don't require root, but you'll need root to
> mount the images.
> 
> As Walter said, it's alarming how many programs fail to handle such
> cases (though D is pretty solid in that regard).
[...]

Very nice! Thanks for sharing. I will keep this in mind next time when I
want to stress-test my program. :-)


T

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