For those of you who don’t already know qemu is a fast and free emulator comparable with VMWare. Of course there are Debian packages available which you could just install as usual but they do not include the closed source kernel module (kqemu) which provides major performance enhancements. So we will compile qemu from source.
Compiling qemu from source
Fetch the qemu source code from the webpage and compile it according to the documentation.
Adjust the configure flag as you like, for example I basically just need support for i386 and since Debian Sid is now using GCC 4.x but qemu doesn’t yet compile with it. I had to point it to an older version as follows:
cd /tmp tar zxvf qemu-0.7.2.tar.gz cd qemu-0.7.2 tar zxvf /tmp/kqemu-0.7.2.tar.gz ./configure --cc=/usr/bin/gcc-3.3 --target-list=i386-softmmu make # and as root make install
To meet a few dependencies I had to further install the two following packages.
apt-get install libsdl1.2-dev apt-get install zlib1g-dev
Per default qemu will be installed in
/usr/local, a new device node
/dev/kqemu should automatically be created. If this is not the case
you should do it manually.
mknod --mode=0666 /dev/kqemu c 250 0
Preparing the kernel for network support via tun/tap devices
If you want your virtual machine connected to the host there are two
different ways to accomplish this. One is with the
line switch which will set up a DHCP server for you (refer to the
documentation for further information), the other is to use tun/tap
devices. For the latter you obviously need tun/tap support activated in
your kernel, below are the relevant settings.
Symbol: TUN [=y] Prompt: Universal TUN/TAP device driver support Defined at drivers/net/Kconfig:85 Depends on: NETDEVICES Location: -> Device Drivers -> Network device support -> Network device support (NETDEVICES [=y]) Selects: CRC32
Afterwards you may have to set appropriate permissions for your
chgrp users /dev/net/tun chmod 660 /dev/net/tun
Creating a virtual disk image
Qemu uses a file to represent the content of the virtual hard disk which can be created as follows.
qemu-img create -f raw win98.img 1000M
The file will grow as more software gets installed to the system.
Installing Windows 98 from a bootable CD
To install Windows you can either boot from the CD or use a boot floppy if you don’t have one download one from here.
Then run qemu with the floppy drive and virtual disk image connected and
let it boot from floopy (
Make sure that you launch the newly compiled qemu which per default is
qemu -hda win98.img -fda /dev/fd0 -boot a
With slightly different options qemu boots from CD.
qemu -hda win98.img -cdrom /dev/hdc -boot d
Additionally you can add an option for your keyboard layout for example
take a look in
/usr/locale/share/qemu/keymaps for valid values.
When Windows first boots up go to the command line by pressing
Shift+F5 and create an empty primary partition on the hard disk with
fdisk, then reboot and proceed with the installation from CD-ROM as you
would do it on a normal computer.
I would recommend to keep the cdrom drive connected to the VM until you successfully logged in the system for the first time, because Windows will need various drivers from it.
When the installation is completed you can boot your image with the command below.
qemu -hda win98.img -boot c
You will probably notice that with Windows 98 as guest the CPU load is very high even if you do nothing special in your VM, this is a known problem and here is the solution.
If you want to change the cdrom while your VM is running then switch to
the QEMU monitor by pressing
Ctrl+Alt+2 and issue the following
eject cdrom change cdrom /dev/cdrom
you can see the changes with
to switch back to the VM use
Set up networking for the virual machine
My network looks like this.
+-------------------------+ +----------------------+ | host pc with debian/sid | ==============> | Router with NAT/DHCP | | eth0: 192.168.1.2/24 | | 192.168.1.1/24 | | tun0: 192.168.2.1/24 | +----------------------+ | gw: 192.168.1.1/24 | || | dns: 192.168.1.1/24 | || +-------------------------+ / / +----------+ || | Internet | || +----------+ +-------------------------+ | qemu with windows 98 | | eth0: 192.168.2.2/24 | | gw: 192.168.2.1/24 | | dns: 192.168.1.1/24 | +-------------------------+
So I had to set up a iptables rule to translate the 192.168.2.x IPs so that the internet is accessible from the Windows box.
Qemu will try to execute
/etc/qemu-ifup on startup to configure the
tun device. The commands in there need root privileges so I created
another file called
/etc/qemu-net-config containing the following.
#!/bin/sh # $1 => tun0 /sbin/ifconfig $1 192.168.2.1 up echo "1" >/proc/sys/net/ipv4/ip_forward iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
Then I configured sudo to allow the user to execute this file without
prompting for a password. Therefore my
/etc/qemu-ifup (which gets
executed by qemu) look like this.
#!/bin/sh sudo /etc/qemu-net-config $1
As a last step, I had to configure the network in Windows IP: 192.168.2.2, gateway: 192.168.2.1 and finally DNS: 192.168.1.1.
With this setup everything worked as expected. After the initial configuration of your VM I would recommend to make a copy of your disk image so you can always switch back to a clean install.
Hope you get it to work too. As a last point I would like to mention the free OS zoo which provides various ready-to-run qemu images.