be used to create a different kind of software-based network. For each card, you can individually select what kind of. When the virtual machine is not running, it is possible to mount partitions that are inside a raw disk image file by setting them up as loopback devices. This does not work with disk images in special formats, such as qcow2, although those can be mounted using qemu-nbd. Four of the network cards can be configured in the. A virtual machine with NAT enabled acts much like a real computer. on the private network from a DHCP server integrated into. for the version without GUI) and below optional packages for your needs:. unexpected application behavior in the guest. This does not cause. of virtual machines, without the need for the host's physical. it looks to the host system as though the guest were physically. A hard disk image can be raw, so that it is literally byte-by-byte the same as what the guest sees, and will always use the full capacity of the guest hard drive on the host. This method provides the least I/O overhead, but can waste a lot of space, as not-used space on the guest cannot be used on the host. use the same ports on the guest and on the host. You can use any. you set up port forwarding. See Section 6.3.1, "Configuring Port Forwarding with NAT". problems with guest operating systems in their default. providing connectivity among virtual machines and the host. Oracle VM VirtualBox also has limited support for. data and resends it using the host operating system. To an. Alternatively, the hard disk image can be in a format such as qcow2 which only allocates space to the image file when the guest operating system actually writes to those sectors on its virtual hard disk. The image appears as the full size to the guest operating system, even though it may take up only a very small amount of space on the host system. This image format also supports QEMU snapshotting functionality (see #Creating and managing snapshots via the monitor console for details). However, using this format instead of raw will likely affect performance. Tip: You can put an entry in /etc/modprobe.d to load the loop module with max_part=15 every time, or you can put loop.max_part=15 on the kernel command-line, depending on whether you have the loop.ko module built into your kernel or not. you select this adapter, then Oracle VM VirtualBox does. not support promiscuous mode. All traffic has to use the MAC. The default user-mode networking allows the guest to access the host OS at the IP address 10.0.2.2. Any servers that you are running on your host OS, such as a SSH server or SMB server, will be accessible at this IP address. So on the guests, you can mount directories exported on the host via SMB or NFS, or you can access the host's HTTP server, etc. It will not be possible for the host OS to access servers running on the guest OS, but this can be done with other network configurations (see #Tap networking with QEMU ).