The Labs.Com OS Lab Qemu

The Labs - Design & Functionality For The Net

A Fast CPU Emulator

I'm quite a fan of virtualization, and VMware was the only commercial product I bought the last years, and it was worth it; but needless to say I was eager to see an open-source replacement or implementation for emulating an entire PC hardware ... and Qemu seems to be it! Not just i386, but also PowerPC (ppc), and other CPUs are under way.

1. First Steps
2. Remote Virtual Machines
3. Webmin Module
4. Netinstall
5. Links

1. FreeBSD: install /usr/ports/emulators/qemu/ port, for other UNIXs check Qemu Homepage
2. Get CDROM ISO: Best search for netinstall ISO images of your favourite OS, e.g. google for "Debian Netinstall". Under FreeBSD use "bootonly" ISO image, aprx. 20MB.
3. Create an empty filesystem: dd if=/dev/zero of=scratch.img bs=1024 count=1000000, creates 1GB file, to be used as virtual harddisk
4. Start Qemu: qemu -cdrom Debian-3.0-netinstall.iso -hda scratch.img -boot d

Qemu 2. Remote Virtual Machines

Currently I develop a webmin module for Qemu for handling virtual machines remotely. For now here a few hints.

Requirements: VNC (see RealVNC.com), its vncviewer actually

Prior qemu-0.8.0 there wasn't a VNC built-in support, now it has it:

On the server:

dd if=/dev/zero of=empty.img bs=1024 count=1500000

qemu -cdrom FreeBSD-5.3-bootonly.iso -hda empty.img -boot d -vnc :1

and on another machine:

vncviewer server:1.0

Attention: Up to version 0.7.2 there are problems with keyboard input (keyscan code translation), check with google for "qemu keyboard problems" for a path, you essentially need to enable SDL keycode translation:

In sdl.c of qemu source code, insert this line at top of file (before the first #include's)

#define CONFIG_SDL_GENERIC_KBD=1

and recompile qemu.

Qemu 3. Webmin Module

History: 2008/03/31: 0.020: fix for process table on solaris, support for linux 2008/03/13: 0.019: supporting solaris as host, thanks to S. Meyer for the patch incl. optional args for qemu 2007/05/12: 0.018: qemu 0.9.0 has -vnc switch now, supporting it 2005/04/02: 0.017: enforcing vncpasswd used to define default passwd for vncserver, first public release 2005/01/03: 0.016: disk image checking if referenced or not (+/- write permission set) 2004/12/30: 0.015: uptime for each vm, more links in the 'connect' page 2004/12/29: 0.014: os image creation (empty), upload not yet working 2004/12/27: 0.013: multiple selection start/halt/etc works now, fixed 2004/12/21: 0.012: qemu.sh and qemutab (auto installs) for autostart (FreeBSD only for now) 2004/12/15: 0.011: multiline comments support 2004/12/08: 0.010: more infos, bug fixes 2004/11/24: 0.009: custom images removed, beautifying code, cleaning up disk format conversion/creation 2004/11/23: 0.008: vmdk, cloop, qcow, cow support, os-images improved, more general os image selection functionality 2004/11/23: 0.007: more detailed infos on viewing/editing vm 2004/11/23: 0.006: vga, port-redirection, as well 'nice' implemented 2004/11/22: 0.005: reboot only restarts qemu, but not Xvnc 2004/11/21: 0.004: code beautifying, cleaner stop/start/reboot, and cpu%/mem% correct (calling fork/exec) 2004/11/21: 0.003: misc bug fixes, iso/img selector fixed, verbose switch added, better preview 2004/11/11: 0.002: file chooser added, for fd[ab], h[abcd], and cdrom 2004/11/11: 0.001: qemu & Xvnc start & stop work, we use root window. 2004/11/05: 0.000: started to code it

Based on the few hints of remote virtual machine I wrote a webmin module called "virtualpc", it gives a web-interface to Qemu. It's early BETA software! I release it for your enjoyment.

Download

virtualpc-0.020.wbm The Virtual PC Webmin Module (frontend for Qemu) Requirements: WebMin, qemu, VNC, and xsetroot, xset (part of X11 distribution), License: GPL fbsd_theme-0.006.wbt FreeBSD Web Console Theme Requirements: WebMin License: GPL Installation: "Webmin" -> "Webmin Configuration" -> "Webmin Theme" and paste URL there.

Installation

Install it via Webmin itself, go to "Webmin" -> "Webmin Configuration" -> "Webmin Modules", and then paste the URL above to "From ftp or http URL", and select that method. The module will be listed under "Network" section. I additionally recommend my "FreeBSD Web Console Theme", which is one of the better designed theme for Webmin I think (based on Linux Management Console by D.V. Dhulla), with nice KDE Crystal icons. More installation notes you find in the running module under "About" then.

Screenshots

Overview of all VMs Detailed View of VM Connected to VM Console via VNC As you see, I run a FreeBSD-5.3 host multiple Linux distributions, NetBSD, yet PPC and SPARC emulation seems broken in the FreeBSD version of Qemu (compiled via FreeBSD ports). FreeBSD-5.3: I noticed also with multiple qemu-sessions running I quickly (within 10 days) run out of kernel memory, I assume this is a FreeBSD-5.x specific problem.

Qemu 4. Netinstall

Here are few links to fetch small netinstall .ISO and boot-floppies:

FreeBSD ISOs choose bootonly or netinstall	NetBSD Floppy FS choose installation/floppy	Debian Netinstall ISO Very well prepared
SuSE i386 choose boot.iso	Fedora Core look for Downloads -> OS -> Images

Most OS do netinstall just fine, as Qemu has DHCP Server build-in and network should be up just fine.

Boot via -cdrom iso-file, or when you used a floppy-image via -fda boot-floppy.

A few hints on netinstall procedures:

FreeBSD

FreeBSD-4.10/i386 and FreeBSD-5.3/i386 as guest works. Status: OK

NetBSD

NetBSD-1.6.2/i386: Just select fda -> NetBSD-boot.fs, and boot fda (for the first boot), and start it with an empty disk at hda; I had problems formating and writing MBR, I continuously run (2-3 times) over it, and finally it worked, make sure you have 700MB+ empty diskimage. When doing ftp install, it failed to lookup ftp.netbsd.org, and I used its direct IP (204.152.190.13), then it worked. Install worked, but system didn't boot properly: system not useable - unfortunately. Status: FAILED NetBSD-2.0/i386: I installed it via full ISO, and after a few hick ups (e.g. I had to define the mount points by hand from /mnt to / and /mnt/usr to /usr), it worked, and booted successfully. Status: OK

Debian

Debian-3.0/i386 works fine Status: OK

Fedora Core 3

i386: Once you booted the small netinstall .iso (which just boots), choose "HTTP" Install Method, select DHCP whenever you are asked, and later enter (there are no intelligent defaults):  Web Site: download.fedora.redhat.com   Path: pub/fedora/linux/core/3/i386/os/  and the rest goes as usual. Fedora Core 3 worked with Qemu-0.6.0 just fine. Status: OK

SuSE 9.1

i386: Set memory to 256MB, otherwise it won't succeed (forget to install SuSE on low memory PCs!) - once you booted it will complain about missing CD1 of SuSE, since I describe here the Netinstall approach it was to be expected, as next "Kernel Modules" -> "Load Network Module Driver" -> "NE-2K PCI", then go back to Network Installation -> FTP, select DHCP Network Setup, once you are asked about IP, then use those (you might lookup ftp.suse.com if the IP below doesn't work):  IP: 195.135.221.132   Path: pub/suse/i386/9.1  as next it will load the ramdisk (quite slowly), after that the GUI installer stops when selecting the language - mouse neither keyboard do respond, so one has to use TAB & RETURN to walk and select GUI options. After installation machine boots and appears useable. Status: OK

Qemu 5. Links

QEMU CPU Emulator Homepage, with lots of useful links	Qemu Launcher GTK2/Perl based GUI for Qemu	KQEMU KDE GUI for Qemu
Qemudo Webinterface (without Webmin)

                                                                                                                                   

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