Are parameters and functions stored in Plasma?

When i run something like

@ray.remote
def my_func(val)
   return 'Hello' + val

my_func.remote('world')

When my_func.remote('world') is executed, does my_func and also the value of the parameter to my_func are serialized and stored in Plasma?

Plasma is used for inter-process transfer of data, your my_func is only a single task that will run on a single raylet, so no, no variables will be written to Plasma.

The function itself will be serialized and sent to the raylet worker, and it will execute it.