mongodb fork in windows

--fork is actually a Linux command not a Windows or mongod command. I do not believe the same exists on Windows at all.

Linux has two primitives here, fork and exec however Windows only really has createProcess which is effectively fork-and-exec.

Setting up a service and running it in fork mode is not the same, a service is more like a init.d script however that is currently the only way really.

Cygwin can emulate fork on Windows, very slowly, as described here: What is the closest thing windows has to fork()?

You can write start /b (/b - means execute without new cmd window) before mongod command. It will start your mongod command asynchronous and release console prompt. So, has similar effect, like fork.

It can be used in .bat scripts, for example, starting replica set:

start /b mongod --replSet m101 --logpath "1.log" --dbpath data\rs1 --port 27017 --smallfiles

start /b mongod --replSet m101 --logpath "2.log" --dbpath data\rs2 --port 27018 --smallfiles

start /b mongod --replSet m101 --logpath "3.log" --dbpath data\rs3 --port 27019 --smallfiles

...