[Qemu-devel] QEMU TUN error with SuSE Linux howto fix

[Till R. Dierkesmann]

Hi together 
 
I've tested the QEMU 0.6 software - it works great. With a workaround I even 
could install OS/2. For installing Windows 95/98 I needed disks, the startup 
from CD didn't work. Is that normal or did I do something wrong? 
 
Windows 95 
- Boot from floppy 
- Windows 95 does not recognize the network card automatically. Where can I 
get a driver for the NE2000 card (or Realtek 8029 chip)?
 
Windows 98 
- Boot from floppy, Installation ok. 
 
How to install OS/2 Warp: 
- Booting from CDRom is not possible. Use the three floppy disks (or copy them 
as image). 
- Sometimes the steps passing through the disks has to be repeated, because 
the QEMU system hung after the start of the third disk. 
- The sound card SB16 has to be selected manually. The screen resolution can't 
be changed to anything else except 640x480, because the system denies using 
another driver except VGA. Additionally after the beginning of the 
installation a crash box appeared within OS/2, but it can be closed and the 
installation goes on. 
- "-localtime" must be supplied for having correct time settings (I use UTC on 
my Linux boxes) 
 
Windows 2000: 
- Installation completed successful without interruption, but it lasted a very 
long time (3 hours on 1.6Ghz machine). I had to prepare a file in the correct 
size before the installation succeeded without storage trouble. For being 
able to use other stuff on the machine I had to renice the qemu process down 
to 19. Some testing resumed in the theory, that the renice did not interfere 
with the Windows performance too much.
 
Windows XP 
- The installation proceeded successful, but very slow (3.5 hours). Even here 
I reniced the process to 19. The main issue seems to be that some stuff is 
executed so slow that the program seems to consume nearly no cpu time, the 
renice is not responsible for the slowlyness. When closing the final black 
window the curious registration key error occurs after restarting. 
 
SuSE Linux 8.1/9.0 
- Installation ok. 
 
SuSE Linux 9.1 
- Installation hangs before the startup of YaST, when trying on QEMU for 
windows (with the japanese patch) - ok, probably I was too unpatient. On 
Linux ok. 
 
The two original scripts which I got for tun are added for comparison issues. 
 
1) Networking with TUN 
The tun network stuff has a the information within the script, that /dev/net/
tun should be writable by the user. The quickest solution to solve the  
seemed to grant _write_ access to /dev/net/tun to all local users. By adding 
the following commands at the beginning of qemu-ifup-sudo.sh it is done 
automatically: 
 
        chgrp users /dev/net/tun 
        chmod g+w /dev/net/tun 
 
2) DHCP 
DHCP didn't start properly. When analyzing I found that the problem seems to 
be that the script works for older dhcp daemons, but not for the daemons 
supplied with SuSE 8.1 and 9.0. They need an additional line like: 
 
        ddns-update-style ad-hoc; 
 
So I changed the script (lines with "a>" added and with "c>" changed): 
 
a>      echo "ddns-update-style ad-hoc;" > /tmp/qemu-dhcpd-$$.conf 
        for N in `seq 40 50` ; do 
            T_NET=192.168.$N.0 
            T_HOST=192.168.$N.1 
            T_RANGE="192.168.$N.2 192.168.$N.100" 
 
            echo "subnet $T_NET netmask 255.255.255.0 {" 
            echo "      option domain-name-servers      $T_HOST;" 
            echo "      option routers                  $T_HOST;" 
            echo "      range                           $T_RANGE;" 
            echo "}" 
c>      done >> /tmp/qemu-dhcpd-$$.conf 
 
3) second session 
Additionally, when starting a second qemu session, it doesn't get an IP. The 
main issue is, that it tries to connect to a further tunX card, but didn't 
give it an ip. The tun parameter hadn't provided in the sudo script 
"sudo_qemu-ifup-sudo.sh". The parameter has to be forwarded: 
 
        sudo /usr/local/bin/qemu-ifup-sudo.sh $* 
 
The path /etc had been used for the scripts, but imho within /etc there should 
be no programs/procedures, so I have moved them to /usr/local/bin) 
 
Again - thank you, Fabrice, very much for your great work! 
 
Friendly regards, Till 
 
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qemu-ifup-sudo.sh
Description: application/shellscript

sudo_qemu-ifup-sudo.sh
Description: application/shellscript