Updates basics_of_linux.md

Knowing how to mount and unmount might be useful if you want to get access to a remote NFS-directory. You will need to mount it to your filesystem to be able to browse it.

It is possible that the disk is not known as `/dev/usb`. If that is the case you can run

```

sudo fdisk -l

```

 And see if you can find your device, and look for the address. Then you mount it like this \(or with the correct path\)

```

sudo mount /dev/sda1

```

#### Mount crypto-volume

```

cryptsetup open /dev/sda1 backup

```

Then you mount it:

```

mount /dev/mapper/backup /media/username/back

```

## 10. Controlling services

### Systemctl