Posts Tagged ‘qemu’

Finally TeamViewer 7 release for GNU / Linux is available

Thursday, March 29th, 2012

 

TeamViewer 7 Debian GNU / Linux released, my desktop screenshot

After a long time of inavailability, finally TeamViewer 7 for GNU / Linux is out!

Here is the short TeamViewer 7 Linux release note :

In our TeamViewer download area you will now find TeamViewer 7 for Linux.
The final version includes a selection of new features for Linux, e. g. an integrated screenshot feature and the possibility of saving individual connection settings per computer.
You can now establish cross platform connections with other computers running version 7 and hold online meetings and presentations with up to 25 participants.

We wish you best continued success with TeamViewer!

Well, guys it was about time, even later than that… Until now I've so many times experienced troubles with Windows machines which I had to administrate remotely and they only had a TeamViewer 7 installed (a real, real pain in the ass).

The issue comes cause TeamViewer 6 is incompatible with 7 and just until very recently only TV 6 for Linux was available, so trying to access a 7 install directly from Linux was impossible.
Hence to access TeamViewer 7 Windows install, I had to use either a fresh Windows copy with TeamViewer 7 installed or a Virtual Machine like (Qemu, VirtualBox) with Windows version installed in it.
Often back then, when I had to fix remotely a Windows machine behind a firewall, I had to instruct the machine owners to replace the TeamViewer 7 with TeamViewer 6 in order to be able to easily access the remote host from my Debian Linux.

I still remember, it was quite a stuggle to find a link to a Windows .exe install file for TeamViewer 6.

Now thanksfully, TeamViewer guys are starting to make it easier for the user who would for some reason want to stick to older TV version.
I've noticed on TeamViewer's website there is already a new TeamViewer download page offering for download all the old teamviewer version – 1.x, 2.x, 3.x, 4.x, 5.x, 6.x

One example, where old teamviewer release is useful is if you want to run teamviewer on older hardware or old OS (MS Windows 98 or old Linux distro).

I've made a mirror of teamviewer 6 for Debian / Ubuntu amd 32 and 64 bit versions along with all the OS available TeamViewer version 6 and 7, for the sake of preserving it if one day link to old versions of Teamviewer disappear from their website.

Here are the TeamViewer mirrored files:

Below you see a screenshot of teamviewer 7 running on my Debian Squeeze 🙂

TeamViewer 7 Debian GNU / Linux released, my desktop screenshot

It is great teamviewer produced a Linux working application, however if you run it you realize just like the previous releases TeamViewer is not natively supposed (compiled) to run on GNU / Linux OS but uses wine (windows emulator) to launch through…
Instead of porting the application to be natively for the Linux distros once again with this new release, teamviewer developers just "hacked" it to run on top of windows emulation. Though this is working its performance, is probably a bit degraded and it depends on having install on the Linux host a bunch of useless packages which wine depends on.
Besides that even if it "works" on Linux , TeamViewer has still non-free software essense. I still use it because unfortunately, I don't know of a better remote access program capable to connect to servers behind NAT / machines located behind a tight firewalled routers.
If only (I knew of?) a TeamViewer free software / open source equivalent
I will be glad to hear if someone know a (free software / open source) TeamViewer like program able to access remote hosts with no a real (public inet) IP address?P.S.: By similar TV program I don't mean VNC, UltraVNC and this kind of other VNC derivative programs but mean close TeamViewer alternative.

How to install VirtualBox Virtual Machine to run Windows XP on Ubuntu Linux (11.10)

Tuesday, January 17th, 2012

Enable_VirtualBox_Windows_XP-fullscreen-with-vboxguest-additions-iso
My beloved sister was complaining games were failing to properly be played with wine emulator , therefore I decided to be kind and help her by installing a Windows XP to run inside a Virtual Machine.My previous install experiments with running MS Windows XP on Linux was on Debian using QEMU virtualmachine emulator.
However as Qemu is a bit less interactive and slower virtualmachine for running Windows (though I prefer it for being completely free software), this time I decided to install the Windows OS with Virtualbox.

My hope was using VirtualBox would be a way easier but I was wrong… I've faced few troubles and I thought many people who initially try to install Virtualbox VM to run Windows on Ubuntu and other Debian based Linux distros will probably experience the same problems as mine, so here is how this article was born.

Here is what I did to have a VirtualBox OS emulator to run Windows XP SP2 on Ubuntu 11.10 Linux

1. Install Virtualbox required packages with apt

root@ubuntu:~# apt-get install virtualbox virtualbox-dkms virtualbox-guest-dkms root@ubuntu:~# apt-get install virtualbox-ose-dkms virtualbox-guest-utils virtualbox-guest-x11
...

If you prefer more GUI or lazy to type commands, the Software Package Manager can also be used to straight install the same packages.
virtualbox-dkms virtualbox-guest-dkms packages are the two which are absolutely necessery in order to enable VirtualBox to support installing Microsoft Windows XP. DKMS modules are also necessery to be able to emulate some other proprietary (non-free) operating systems.
The DKMS packages provide a source for building Vbox guest (OS) additional kernel modules. They also require the kernel source to be install otherwise they fail to compile.

Failing to build the DKMS modules will give you error every time you try to create new VirtualMachine container for installing a fresh Windows XP.
The error happens if the two packages do not properly build the vboxdrv extra Vbox kernel module while the Windows XP installer is loaded from a CD or ISO. The error to pop up is:

Kernel driver not installed (rc=-1908)

The VirtualBox Linux kernel driver (vboxdrv) is either not loaded or there is a permission problem with /dev/vboxdrv. Please reinstall the kernel module by executing

VirtualBox vboxdrv not loaded error Ubuntu Screen

To fix the error:

2. Install latest Kernel source that corresponds to your current kernel version

root@ubuntu:~# apt-get install linux-headers-`uname -r`
...

Next its necessery to rebuild the DKMS modules using dpkg-reconfigure:

3. Rebuild VirtualBox DKMS deb packages

root@ubuntu:~# dpkg-reconfigure virtualbox-dkms
...
root@ubuntu:~# dpkg-reconfigure virtualbox-guest-dkms
...
root@ubuntu:~# dpkg-reconfigure virtualbox-ose-dkms
...

Hopefully the copilation of vboxdrv kernel module should complete succesfully.
To test if all is fine just load the module:

4. Load vboxdrv virtualbox kernel module

root@ubuntu:~# modprobe vboxdrv
root@ubuntu:~#

If you get some error during loading, this means vboxdrv failed to properly compile, try read thoroughfully what the error is and fix it) ;).

As a next step the vboxdrv has to be set to load on every system boot.

5. Set vboxdrv to load on every Ubuntu boot

root@ubuntu:~# echo 'vboxdrv' >> /etc/modules

I am not sure if this step is required, it could be /etc/init.d/virtualbox init script automatically loads the module, anyways putting it to load on boot would do no harm, so better do it.

That's all now, you can launch VirtualBox and use the New button to initiate a new Virtual Machine, I will skip explaining how to do the configurations for a Windows XP as most of the configurations offered by default would simply work without any tampering.

After booting the Windows XP installer I simply followed the usual steps to install Windows and all went smoothly.
Below you see a screenshot showing the installed Windows XP Virtualbox saved VM session. The screenshot letters are in Bulgarian as my sisters default lanaguage for Ubuntu is bulgarian 😉

VirtualBox installed MS Windows VM screenshot

I hope this article helps someone out there. Please drop me a comment if you experience any troubles with it. Cya 🙂

How to configure and enable Xen Linux dedicated server’s Virtual machines Internet to work / Enable multipe real IPs and one MAC only in (SolusVM) through NAT routed and iptables

Saturday, June 4th, 2011

Xen Linux Virtual Machine Logo

I’ve been hired as a consultant recently to solve a small task on a newly bought Xen based dedicated server.
The server had installed on itself SolusVM

The server was a good hard-iron machine running with CentOS Linux with enabled Xen virtualization support.
The Data Center (DC) has provided the client with 4 IP public addresses, whether the machine was assigned to possess only one MAC address!

The original idea was the dedicated server is supposed to use 4 of the IP addresses assigned by the DC whether only one of the IPs has an external internet connected ethernet interface with assigned MAC address.

In that case using Xen’s bridging capabilities was pretty much impossible and therefore Xen’s routing mode has to be used, plus an Iptables Network Address Translation or an IP MASQUERADE .

In overall the server would have contained 3 virtual machines inside the Xen installed with 3 copies of:

  • Microsoft Windows 2008

The scenario I had to deal with is pretty much explained in Xen’s Networking wiki Two Way Routed Network

In this article I will describe as thoroughfully as I can how I configured the server to be able to use the 3 qemu virtual machines (running inside the Xen) with their respective real interner visible public IP addresses.

1. Enable Proxyarp for the eth0 interface

To enable proxyarp for eth0 on boot time and in real time on the server issue the commands:

[root@centos ~]# echo 1 > /proc/sys/net/ipv4/conf/eth0/proxy_arp[root@centos ~]# echo 'net.ipv4.conf.all.proxy_arp = 1' >> /etc/sysctl.conf

2. Enable IP packet forwarding for eth interfaces

This is important pre-requirement in order to make the iptables NAT to work.

[root@centos ~]# echo 'net.ipv4.ip_forward = 1' >> /etc/sysctl.conf
[root@centos ~]# echo 'net.ipv6.conf.all.forwarding=1' >> /etc/sysctl.conf

If you get errors during execution of /etc/init.d/xendomains , like for example:

[root@centos ~]# /etc/init.d/xendomains restart
/etc/xen/scripts/network-route: line 29: /proc/sys/net/ipv4/conf/eth0/proxy_arp: No such file or directory
/etc/xen/scripts/network-route: line 29: /proc/sys/net/ipv6/conf/eth0/proxy_arp: No such file or directory

in order to get rid of the message you will have to edit /etc/xen/scripts/network-route and comment out the lines:

echo 1 >/proc/sys/net/ipv4/conf/${netdev}/proxy_arp
echo 1 > /proc/sys/net/ipv6/conf/eth0/proxy_arp
e.g.
#echo 1 >/proc/sys/net/ipv4/conf/${netdev}/proxy_arp
#echo 1 > /proc/sys/net/ipv6/conf/eth0/proxy_arp

3. Edit /etc/xen/xend-config.sxp, disable ethernet bridging and enable eth0 routing (route mode) and NAT for Xen’s routed mode

Make absolutely sure that in /etc/xen/xend-config.sxp the lines related to bridging are commented.
The lines you need to comment out are:

(network-script network-bridge)
(vif-script vif-bridge)

make them look like:

#(network-script network-bridge)
#(vif-script vif-bridge)br />

Now as bridging is disabled let’s enable Xen routed network traffic as an bridged networking alternative.

Find the commented (network-script network-route) and (vif-script vif-route) lines and uncomment them:

#(network-script network-route)
#(vif-script vif-route)

The above commented lines should become:

(network-script network-route)
(vif-script vif-route)

Next step is to enable NAT for routed traffic in Xen (necessery to make routed mode work).
Below commented two lines in /etc/xen/xend-config.sxp, should be uncommented e.g.:

#(network-script network-nat)
#(vif-script vif-nat)

Should become:

(network-script network-nat)
(vif-script vif-nat)

4. Restart Xen control daemon and reload installed Xen’s Virtual Machines installed domains

To do so invoke the commands:

[root@centos ~]# /etc/init.d/xend
[root@centos ~]# /etc/init.d/xendomains restart

This two commands will probably take about 7 to 10 minutes (at least they took this serious amount of time in my case).
If you think this time is too much to speed-up the procedure of restarting Xen and qemu attached virtual machines, restart the whole Linux server, e.g.:

[root@centos ~]# restart

5. Configure iptables NAT rules on the CentOS host

After the server boots up, you will have to initiate the following ifconfig & iptables rules in order to make the Iptables NAT to work out:

echo > > /proc/sys/net/ipv4/conf/tap1.0/proxy_arp
/sbin/ifconfig eth0:1 11.22.33.44 netmask 255.255.252.0
/sbin/ifconfig eth0:2 22.33.44.55 netmask 255.255.252.0
/sbin/ifconfig eth0:3 33.44.55.66 netmask 255.255.252.0

/sbin/iptables -t nat -A PREROUTING -d 11.22.33.44 -i eth0 -j DNAT --to-destination 192.168.1.2
/sbin/iptables -t nat -A PREROUTING -d 22.33.44.55 -i eth0 -j DNAT --to-destination 192.168.1.3
/sbin/iptables -t nat -A PREROUTING -d 33.44.55.66 -i eth0 -j DNAT --to-destination 192.168.1.4
/sbin/iptables -t nat -A POSTROUTING -s 192.168.1.2 -o eth0 -j SNAT --to-source 11.22.33.44
/sbin/iptables -t nat -A POSTROUTING -s 192.168.1.3 -o eth0 -j SNAT --to-source 22.33.44.55
/sbin/iptables -t nat -A POSTROUTING -s 192.168.1.4 -o eth0 -j SNAT --to-source 33.44.55.66

In the above ifconfig and iptables rules the IP addresses:

11.22.33.44, 22.33.44.55, 33.44.55.66 are real IP addresses visible from the Internet.
In the above rules eth0:1, eth0:2 and eth0:3 are virtual ips assigned to the main eth0 interface.

This ifconfig and iptables setup assumes that the 3 Windows virtual machines running inside the Xen dedicated server will be configured to use (local) private network IP addresses:

192.168.1.2, 192.168.1.3 and 192.168.1.4

You will have also to substitute the 11.22.33.44, 22.33.44.55 and 33.44.55.66 with your real IP addreses.

To store the iptables rules permanently on the fedora you can use the iptables-save command:

[root@centos ~]# /sbin/iptables-save

However I personally did not use this approach to save my inserserted iptable rules for later boots but I use my small script set_ips.sh to add virtual interfaces and iptables rules via the /etc/rc.local invokation:

If you like the way I have integrated my virtual eths initiation and iptables kernel firewall inclusion, download my script and set it to run in /etc/rc.local, like so:

[root@centos ~]# cd /usr/sbin
[root@centos sbin]# wget http://www.pc-freak.net/bshscr/set_ips.sh
...
[root@centos ~]# chmod +x /usr/sbin/set_ips.sh
[root@centos ~]# mv set_ips.sh /usr/sbin
[root@centos ~]# echo '/usr/sbin/set_ips.sh' >> /etc/rc.local

Note that you will have to modify my set_ips.sh script to substitute the 11.22.33.44, 22.33.44.55 and 33.44.55.66 with your real IP address.

So far so good, one might think that all this should be enough for the Virtual Machines Windows hosts to be able to connect to the Internet and Internet requests to the virtual machines to arrive, but no it’s not!!

6. Debugging Limited Connectivity Windows LAN troubles on the Xen dedicated server

Even though the iptables rules were correct and the vif route and vif nat was enabled inside the Xen node, as well as everything was correctly configured in the Windows 2008 host Virtual machines, the virtual machines’s LAN cards were not able to connect properly to connect to the internet and the Windows LAN interface kept constantly showing Limited Connectivity! , neither a ping was available to the gateway configured for the Windows VM host (which in my case was: 192.168.1.1).

You see the error with Limited connectivity inside the Windows on below’s screenshot:

Limited Connectivty Windows error Lan Interface, status screenshot

Here is also a screenshot of my VNC connection to the Virtual machine with the correct IP settings – (TCP/IPv4) Properties Window:

Windows Xen Network Connections Windows VNC TCP/IPv4 Properties Window

This kind of Limited Connectivity VM Windows error was really strange and hard to diagnose, thus I started investigating what is wrong with this whole situation and why is not able the Virtualized Windows to connect properly to the Internet, through the Iptables NAT inbound and outbound traffic redirection.

To diagnose the problem, I started up with listing the exact network interfaces showing to be on the Xen Dedicated server:


[root@centos ~]# /sbin/ifconfig |grep -i 'Link encap' -A 1
eth0 Link encap:Ethernet HWaddr 00:19:99:9C:08:3A
inet addr:111.22.33.55 Bcast:111.22.33.255
Mask:255.255.252.0
--
eth0:1 Link encap:Ethernet HWaddr 00:19:99:9C:08:3A
inet addr:11.22.33.44 Bcast:11.22.33.255
Mask:255.255.252.0
--
eth0:2 Link encap:Ethernet HWaddr 00:19:99:9C:08:3A
inet addr:22.33.44.55 Bcast:22.33.44.255
Mask:255.255.252.0
--
eth0:3 Link encap:Ethernet HWaddr 00:19:99:9C:08:3A
inet addr:33.44.55.66 Bcast:33.44.55.255
Mask:255.255.252.0
--
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
--
tap1.0 Link encap:Ethernet HWaddr FA:07:EF:CA:13:31
--
vifvm101.0 Link encap:Ethernet HWaddr FE:FF:FF:FF:FF:FF
inet addr:111.22.33.55 Bcast:111.22.33.55
Mask:255.255.255.255

I started debugging the issue, using the expelling logic.
In the output concerning my interfaces via ifconfig on eth0, I have my primary server IP address 111.22.33.55 , this one is working for sure as I was currently connected to the server through it.

The other virtual IP addresses assigned on the virtual network interfaces eth0:1, eth0:2 and eth0:3 were also assigned correctly as I was able to ping this ips from my Desktop machine from the Internet.

The lo , interface was also properly configured as I could ping without a problem the loopback ip – 127.0.0.1

The rest of the interfaces displayed by my ifconfig output were: tap1.0, vifvm101.0

After a bit of ressearch, I’ve figured out that they’re virtual interfaces and they belong to the Xen domains which are running qemu virtual machines with the Windows host.

I used tcpdump to debug what kind of traffic does flow through the tap1.0 and vifvm101.0 interfaces, like so

[root@centos ~]# tcpdump -i vifvm101.0
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on vifvm101.0, link-type EN10MB (Ethernet), capture size 96 bytes
^C
0 packets captured
0 packets received by filter
0 packets dropped by kernel
[root@centos ~]# tcpdump -i tap1.0
cpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on tap1.0, link-type EN10MB (Ethernet), capture size 96 bytes
^C
08:55:52.490249 IP 229.197.34.95.customer.cdi.no.15685 > 192.168.1.2.12857: UDP, length 42

I’ve figured out as it’s also observable in above’s two tcpdump commands output, that nothing flows through the vifvm101.0 interface, and that there was some traffic passing by tap1.0 interface.

7. Solving the Limited Connectivy Windows Internet network connection problems

As below’s ifconfig output reveals, there is no IP address assigned to tap1.0 interface, using some guidelines and suggestions from guys in irc.freenode.net’s #netfilter irc channel, I’ve decided to give a go to set up an IP address of 192.168.1.1 to tap1.0 .

I choose for a reason as this IP address is configured to be my Gateway’s IP Address inside the Emulated Windows 2008 hosts

To assign the 192.168.1.1 to tap1.0, I issued:

[root@centos ~]# /sbin/ifconfig tap1.0 192.168.1.1 netmask 255.255.255.0
To test if there is difference I logged in to the Virtual Machine host with gtkvncviewer (which by the way is a very nice VNC client for Gnome) and noticed there was an established connection to the internet inside the Virtual Machine 😉

I issued a ping to google which was also returned and opened a browser to really test if everything is fine with the Internet.
Thanks God! I could browse and everything was fine 😉

8. Making tap1.0 192.168.1.1 (VM hosts gateway to be set automatically, each time server reboots)

After rebooting the server the tap1.0 assignmend of 192.168.1.1 disappeared thus I had to make the 192.168.1.1, be assigned automatically each time the CentoS server boots.

To give it a try, I decided to place /sbin/ifconfig tap1.0 192.168.1.1 netmask 255.255.255.0 into /etc/rc.local, but this worked not as the tap1.0 interface got initialized a while after all the xendomains gets initialized.

I tried few times to set some kind of sleep time interval with the sleep , right before the /sbin/ifconfig tap1.0 … ip initialization but this did not worked out, so I finally completely abandoned this methodology and make the tap1.0 get initialized with an IP through a cron daemon.
For that purpose I’ve created a script to be invoked, every two minutes via cron which checked if the tap1.0 interface is up and if not issues the ifconfig command to initialize the interface and assign the 192.168.1.1 IP to it.

Here is my set_tap_1_iface.sh shell script

To set it up on your host in /usr/sbin issue:

[root@centos ~]# cd /usr/sbin/
[root@centos sbin]# wget http://www.pc-freak.net/bshscr/set_tap_1_iface.sh
...
In order to set it on cron to make the tap1.0 initialization automatically every two minutes use the cmd:

[root@centos ~]# crontab -u root -e

After the cronedit opens up, place the set_tap_1_iface.sh cron invokation rules:

*/2 * * * * /usr/sbin/set_tap_1_iface.sh >/dev/null 2>&1

and save.

That’s all now your Xen dedicated and the installed virtual machines with their public internet IPs will work 😉
If this article helped you to configure your NAT routing in Xen drop me a thanks message, buy me a beer or hire me! Cheers 😉

Knowing Not! :]

Monday, January 22nd, 2007

Today I have Marketing exam. Ofcourse as usual when I have exams I haven’t studied enough, and again I’m in the situation realizing I don’t know anything. I depend 100% on God’s grace to take that exam. Why I’m so dumb never study when

I have what I have. I can’t change my self I can’t study something I’m not interested into. Marketing is a subject which is simple but for Jerks IMHO :]. The logic of marketing is too abstract.

And yes what’s happening with me the last days. Well I’m feeling good now Praise the Lord. I’ve no idea what I should do with my life. I have 2 re-exams for now or maybe 3 ( I don’t know the results from the Research & Statistics Exam ).

The last few days I ran FreeDOS and Windows 2000 Pro SP4 under FreeBSD 6.2 with qemu. FreeDOS’s performance is very nice despite the fact it is emulated. The Windows is running a little laggish although I ran it with kqemu ( Experimental Module for qemu which enhances the typical qemu speed ). Yesterday we drink a dark beer with Nomen into the “Happy Person” Pub. My passion for computers is starting to come back again.