Please keep in mind that, similarly to many other computationally-intensive tasks, fuzzing may put a strain on your hardware and on the OS. In particular:
Your CPU will run hot and will need adequate cooling. In most cases, if cooling is insufficient or stops working properly, CPU speeds will be automatically throttled. That said, especially when fuzzing on less suitable hardware (laptops, smartphones, etc), it's not entirely impossible for something to blow up.
Targeted programs may end up erratically grabbing gigabytes of memory or filling up disk space with junk files. AFL++ tries to enforce basic memory limits, but can‘t prevent each and every possible mishap. The bottom line is that you shouldn’t be fuzzing on systems where the prospect of data loss is not an acceptable risk.
Fuzzing involves billions of reads and writes to the filesystem. On modern systems, this will be usually heavily cached, resulting in fairly modest “physical” I/O - but there are many factors that may alter this equation. It is your responsibility to monitor for potential trouble; with very heavy I/O, the lifespan of many HDDs and SSDs may be reduced.
A good way to monitor disk I/O on Linux is the ‘iostat’ command:
$ iostat -d 3 -x -k [...optional disk ID...]
Using the `AFL_TMPDIR` environment variable and a RAM-disk you can have the heavy writing done in RAM to prevent the aforementioned wear and tear. For example the following line will run a Docker container with all this preset: ```shell # docker run -ti --mount type=tmpfs,destination=/ramdisk -e AFL_TMPDIR=/ramdisk aflplusplus/aflplusplus ```