# Sessions Runs live in a session, and you create one with `machine sessions create`. Pick its size when you create it. ```bash machine sessions create ci-1 --cpus 4 --mem 8G ``` `--cpus` sets the number of vCPUs, `--mem` the memory and `--storage` the disk space. `--class` picks the hardware class, and the default comes from your plan. The name is optional, so leave it off and Machine makes one up. Machine waits until the session is running and tells you when it is. Add `--no-wait` if you would rather it didn't. Creating a session doesn't switch you to it. Tell Machine which one to use. ```bash machine sessions use ci-1 ``` `machine sessions use` applies to the terminal you ran it in. For scripts, set `TESTFLOWS_MACHINE_SESSION=ci-1` instead, and every command goes to that session. If you only have one session, `machine sessions use` needs no name at all. After that, every command that needs a machine goes to `ci-1`. You can send one command somewhere else with `-s`, for example `machine -s ci-2 runs`. You manage the rest of your sessions like this: ```bash machine sessions list machine sessions show ci-1 machine sessions rename ci-1 ci-2 machine sessions delete ci-2 ``` > **{% attention %}** Delete sessions you are not using. A session costs from > the moment you create it, whether or not anything is running in it.