Following are the details of my system: Fedora Core-18, i686.
I am trying to install ubuntu in the qemu. Following are the commands I executed:
qemu-img create ubuntu.img 8G
qemu-system-i386 -hda ubuntu.img -boot d -cdrom ./ubuntu-13.10-desktop-i386.iso -m 512
After executing the second command the window pops up and it shows UBUNTU getting started but after that the window just becomes black with no activity.
The problem is that you are emulating and not virtualizing, and emulating is resource consuming, so the boot takes a very long time to finish.
To speed things up, add the -enable-kvm flag to enable KVM virtualization:
qemu-system-i386 -hda ubuntu.img -boot d -cdrom ./ubuntu-13.10-desktop-i386.iso -m 512 -enable-kvm
This has also been asked at: https://askubuntu.com/questions/419958/why-am-i-getting-a-black-screen-when-booting-vm-using-qemu
You don't specify whether you're using QEMU or KVM, but as @BodhiZazen said in the comments, I don't think vanilla QEMU can support high end graphics such as what Unity requires.
If you're actually trying to use KVM, then I'd recommend using the GUI tool virt-manager to perform your VM Guest installations rather than the command line. It's easier to mount ISO media and reconfigure the Guest VM through the GUI.
You can see more of virt-manager in action on the project's website and read about it features there as well.
Working Ubuntu 18.04 host / guest setup
I cannot reproduce with the following setup:
wget http://releases.ubuntu.com/xenial/ubuntu-18.04-desktop-amd64.iso
qemu-img create -f qcow2 ubuntu-18.04-desktop-amd64.img.qcow2 16G
qemu-system-x86_64 \
-cdrom ubuntu-18.04-desktop-amd64.iso \
-drive file=ubuntu-18.04-desktop-amd64.qcow2,format=qcow2 \
-enable-kvm \
-m 2G \
-smp 2 \
-vga virtio \
;
Then on the GUI:
After the install is complete, I recommend using a disk snapshot in case you ever want to go back to the pristine install (a common use case for testing software):
qemu-img create -f qcow2 -b ubuntu-18.04-desktop-amd64.qcow2 \
ubuntu-18.04-desktop-amd64.snapshot.qcow2
and then restart the system from the snapshot disk:
qemu-system-x86_64 \
-drive file=ubuntu-18.04-desktop-amd64.snapshot.qcow2,format=qcow2 \
-enable-kvm \
-m 2G \
-smp 2 \
-vga virtio \
;
Then anytime you want to go back to the pristine install, just re-run:
qemu-img create -f qcow2 -b ubuntu-18.04-desktop-amd64.qcow2 \
ubuntu-18.04-desktop-amd64.snapshot.qcow2
The snapshot only stores the diffs between the original image, and so it does not take a lot of disk space.
Tested on an Ubuntu 18.04 host, QEMU 1:2.11+dfsg-1ubuntu7.3, nvidia-384 version 390.48-0ubuntu3, Lenovo ThinkPad P51, NVIDIA Corporation GM107GLM [Quadro M1200 Mobile] GPU.
Notes:
-vga virtio option is to be able to get higher resolutions: https://superuser.com/questions/132322/how-to-increase-the-visualized-screen-resolution-on-qemu-kvm/1331924#1331924 Toggle full screen with:
Ctrl + Alt + F
of start QEMU with -full-screen.
-soundhw hda enables sound. Why does not QEMU enable it by default beats me.
Once inside the VM, reduce the GRUB menu wait time and show some boot messages for next boot with:
printf 'GRUB_TIMEOUT=1\nGRUB_CMDLINE_LINUX_DEFAULT=""\n' | sudo tee -a /etc/default/grub
sudo update-grub
TODO clipboard sharing:
Tried -spice port=5930,disable-ticketing + remote-viewer spice://127.0.0.1:5930, and spice-vdagent is pre-installed on guest, but no success.
The root cause of the mess is that QEMU devs seem more focused on non-interactive usage, rather than implementing things like this reliably and therefore killing VirtualBox once and for all: https://bugs.launchpad.net/qemu/+bug/614958
TODO: host 3D acceleration. Still with SPICE and QXL, glxgears gives 1k FPS, and the exact same with regular SDL. But on host __GL_SYNC_TO_VBLANK=0 vblank_mode=0 glxgears gives 20k FPS, so I'm guessing graphics were not accelerated?
Related: How to install Ubuntu 13.10 Desktop in QEMU?
Prebuilt bootable images
If you want an image that boots without the need for any interaction on the installer, see: https://askubuntu.com/questions/281763/is-there-any-prebuilt-qemu-ubuntu-image32bit-online