Small Virtual Machines
Existing forum message shows how to create small Debian and ReactOS virtual machines using Qemu [[1]]
ReactOS virtual machine
I just built (on Ubuntu 12.04) a minimal i386 VM with QEMU with ReactOS 0.3.17.
Download from ReactOS ReactOS-0.3.17-REL-iso.zip (88MB) and unzip to get ReactOS-BootCD.iso (103MB)
qemu-img create -f qcow2 reactos0317.img 2G
qemu-system-i386 -m 512 -hda reactos0317.img -cdrom ReactOS-BootCD.iso -boot d
For the install I just pressed <Enter> for everything. When it reboots (twice) don't hit any key so it won't boot from the CD.
Shut down ReactOS. The QEMU image file is 280MB.
Restart with networking:
qemu-system-i386 -m 512 -hda reactos0317.img -boot c -net nic -net user
In the VM double-click on the Command Prompt and run ipconfig.
No, you don't want to use ReactOS for your desktop operating system, but it might be good enough to use for some specific things (like putting in a small VM).
Debian virtual machine
I recently built (on Ubuntu 14.04) a minimal i386 VM with QEMU with Debian (new version 8 release) Jessie.
Dowload debian-8.0.0-i386-netinst.iso (330 MB) and rename to debjes.iso
qemu-img create -f qcow2 debjes.img 2G
qemu-system-i386 -m 512 -hda debjes.img -cdrom debjes.iso -boot d
Networking worked without having to add other command line parameters! I removed the 2 default software collections (near the end of the install). The QEMU image file is 1.3 GB.
In the VM:
add sudo (I have instruction near the bottom of this page: Control Pascal PicoScope)
sudo apt-get clean
sudo dd if=/dev/zero of=/mytempfile
sudo rm -f /mytempfile
sudo halt
After this the new img file is 635 MB:
qemu-img convert -O qcow2 debjes.img debjesnew.img
Archive with 7z and the file is now 143 MB. Not very big for a nice new Debian console VM.
Notes
On Ubuntu kvm can be substituted for quem-system-i386 and things work much faster.
