Hi, first of all: many thanks to Ion, it was very helpful. But here is my next problem: Can I and how can I increase the size of a shared memory segment? I've my map<string, string> successfully put into shared memory, but at the moment I have to give the size of the segment when creating it boost::interprocess::managed_shared_memory segment(boost::interprocess::create_only, "MySharedMemory" ,65536); Is there a way to increase this size? I don't want to start with say 10M, but under certain circumstances I might require 10M. There is a truncate method in shared_memory_object. Is there something similar for managed_shared_memory? Or is managed_shared_memory a shared_memory_object? Or is there a way to configure a managed_shared_memory object to increase automatically if required? Thanks, Wolfgang