Limit Number of concurrent processes

[ericschreiber]

Is there an easy way of limiting the number of concurrent processes that are being used during plan&preprocess, training and prediction? I work with large images s.t. my MEM does not suffice for multiple concurrent processes. The code fails if I run it on multiple images.
I saw, that I can set the environment variable nnUNet_def_n_proc=1 and this should give me a default of 1 Process instead of 8. But it does not seem to be working well. I always get more.