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Re: Laptops and Virtulization



On Tuesday 23 September 2008 14:05:52 Clifford W. Hansen wrote:
> On Tuesday 23 September 2008 19:30:20 Clifford W. Hansen wrote:
> > On Tuesday 23 September 2008 13:16:11 Joseph Rawson wrote:
> > > On Monday 22 September 2008 13:41:38 Clifford W. Hansen wrote:
> > > > On Friday 19 September 2008 09:56:11 Clifford W. Hansen wrote:
> > > > > On Friday 19 September 2008 09:38:04 Stephan Peijnik wrote:
> > > > > > On Fri, 2008-09-19 at 08:59 +0200, Clifford W. Hansen wrote:
> > > > > > > I would like to find out from the list what they use on there
> > > > > > > laptops for virtulization.
> > > > > > >
> > > > > > > I'm needing to run a vm on my laptop for using as a development
> > > > > > > server, and I need it to be able to access the network my wifi
> > > > > > > card is attached to.
> > > > > > >
> > > > > > > I have scoured the interweb and havn't found what I'm looking
> > > > > > > for (other then vmware which has some issues)
> > > > > > >
> > > > > > > I would prefer to run the latest etch-n-half kernel, possibly
> > > > > > > even lenny although I don't have lenny yet.
> > > > > >
> > > > > > Personally I am using VirtualBox OSE for exact the reason you
> > > > > > would like virtualization.
> > > > > >
> > > > > > After a quick check virtualbox-ose is either available within
> > > > > > Lenny (including the kernel module) or via etch-backports where
> > > > > > you need to build the kernel module yourself though.
> > > > > >
> > > > > > For a list of packages available in Debian check
> > > > > > http://packages.debian.org/search?keywords=virtualbox-ose.
> > > > > >
> > > > > > Regards,
> > > > > >
> > > > > > Stephan
> > > > >
> > > > > Stephan,
> > > > >
> > > > > I was using VirtualBox for a while, but could never get the bridged
> > > > > mode working due to my laptop connecting via wifi, but then again
> > > > > no one else needs to access my dev box anymore. Well DHCP wasn't
> > > > > working.
> > > > >
> > > > > Will give it a bash again, thank you...
> > > >
> > > > Just for future reference / anyone who is interested I got the
> > > > following working.
> > > >
> > > > And it almost does exactly what I need, well it's good enough for
> > > > now: <vbox-networking.sh>
> > > > #!/bin/bash
> > > >
> > > > LAN="eth1"
> > > > DHCP_SERVER="xxx.xxx.xxx.xxx"
> > > >
> > > > case "${1}" in
> > > >         "start" )
> > > >                 TAP=$(VBoxTunctl -b -u clifford)
> > > >                 echo ${TAP} > /var/run/vbox.tap
> > > >                 sysctl net.ipv4.ip_forward=1 >> /dev/null
> > > >                 ip link set ${TAP} up
> > > >                 ip addr add xxx.xxx.xxx.xxx/xx dev ${TAP}
> > > >                 parprouted ${LAN} ${TAP}
> > > >                 iptables -t nat -A POSTROUTING -o ${LAN} -j
> > > > MASQUERADE dhcrelay3 -q -i ${LAN} -i ${TAP} ${DHCP_SERVER} echo
> > > > ${TAP}
> > > >                 ;;
> > > >         "stop" )
> > > >                 TAP=${3}
> > > >                 kill -9 $(ps -elf | grep ${TAP} | grep -v grep | awk
> > > > '{print $4}' | grep -v $$)
> > > >                 ifconfig ${TAP} down
> > > >                 VBoxTunctl -d ${TAP} >> /dev/null
> > > >                 sysctl net.ipv4.ip_forward=0 >> /dev/null
> > > >                 ;;
> > > > esac
> > > > </vbox-networking.sh>
> > > >
> > > > This can then be used by VirtualBox as the network script (Network
> > > > --> Host interface settings --> Setup/Terminate)
> > > >
> > > > I just run these as "sudo /path/to/vbox-networking.sh start" and it
> > > > does the rest.
> > > >
> > > > Unfortunately due to using parprouted it seems like it's not
> > > > accessable from the lan, but I'm working on this... The solutions
> > > > possibly has something to do with a bridge...
> > >
> > > I thought about replying to you when you first posted, but I didn't
> > > know how to respond to bridging over wifi.  The debian wiki has some
> > > pretty good info on setting up a bridge for virtualbox.  A few weeks
> > > ago, I updated the example script that brings the interface up and
> > > down, and added a snippet of my sudoers file that lets you run the
> > > particular commands without using a password.  On my system, all the
> > > tap interfaces are named
> > > vbox_{$vboxname}, and everything seems to be working just fine.
> > >
> > > Here's the page: http://wiki.debian.org/VirtualBox
> > >
> > > I didn't like adding the tap interfaces to /etc/vbox/interfaces, and I
> > > think that the solution on the wiki page is much better than having to
> > > list static interfaces there.
> > >
> > > Btw, I've never heard of parprouted before.  I just looked up the
> > > package and it seems interesting.  I might play with this later.
> > >
> > > Using an ethernet bridge can be painful on a laptop sometimes, like
> > > when there's no dhcp server on the network, and you have to give the
> > > br0 a static address.  That makes it much more difficult when the VM's
> > > are also expecting to get their network info from dhcp.  There are also
> > > problems when there is a dhcp server, but there's no dns updates for
> > > the hostnames. This can get to be annoying when you're using many VM's.
> >
> > Just done some testing using a bridge, I've managed to get this part to
> > work, and VBox sets up the tap devices as required, the only problem is
> > that the vm can't see the network only the devices attached to the
> > bridge.
> >
> > Although, doing all of this and attaching the bridge to the wired
> > connection works... :/
> >
> > The main problem I have with my previous method is that other machines on
> > the lan cannot see my vm's...
> >
> > Why and how does VMWare get this right (ok other than having money thrown
> > at it :p )
>
> OK to kind of answer my own question :(
>
> Taken from: http://www.linuxfoundation.org/en/Net:Bridge
> <quote>
> ** It doesn't work with my Wireless card! **
>
> This is a known problem, and it is not caused by the bridge code. Many
> wireless cards don't allow spoofing of the source address. It is a firmware
> restriction with some chipsets. You might find some information in the
> bridge mailing list archives to help. Has anyone found a way to get around
> Wavelan not allowing anything but its own MAC address? (answer by Michael
> Renzmann (mrenzmann at compulan.de))
>
> Well, for 99% of computer users there will never be a way to get rid of
> this. For this function a special firmware is needed. This firmware can be
> loaded into the RAM of any WaveLAN card, so it could do its job with
> bridging. But there is no documentation on the interface available to the
> public. The only way to achieve this is to have a full version of the hcf
> library which controls every function of the card and also allows accessing
> the card's RAM. To get this full version Lucent wants to know that it will
> be a financial win for them, also you have to sign an NDA. So be sure that
> you won't most probably get access to this peace of software until Lucent
> does not change its mind in this (which I doubt never will happen).
>
> If you urgently need to have a wireless LAN card which is able to bridge,
> you should use one of those having the prism chipset onboard (manufactured
> by Harris Intersil). There are drivers for those cards available at
> www.linux-wlan.com (which is the website from Absoval), and I found a mail
> that says that there is the necessary firmware and an upload tool available
> for Linux to the public. If you need additional features of an access point
> you should also talk to Absoval.
>
> ** I still don't understand!! **
>
> Doing full bridging of wireless (802.11) requires supporting WDS . The
> current implementation doesn't do it.
>
> It is possible to do limited wireless to Ethernet functionality with some
> wireless drivers. This requires the device to be able to support a
> different sender address and source address. That is what WDS provides.
>
> There are ways to make it work, but it is not always straightforward and
> you probably won't get it right without a pretty solid understanding of
> 802.11, it's modes, and the frame header format.
> </quote>

I figured that there would be problems bridging wireless devices.  This is why 
I didn't reply to you on your first couple of posts.  When I saw the script 
that you wrote, and saw that it uses eth1, that's when I figured that you 
weren't using wireless.  I'm a absolute noob when it comes to using wireless.  
I'm on my third laptop using built in wireless, and I still have yet to 
actually use it further than testing it in windows to see if it works before 
I install debian.

I'm sorry, from what I was reading, I was thinking that you were just going to 
use regular ethernet to run you're VM's.  The only thing I know to do to get 
the VM's available over the wireless is to use DNAT and port forwarding.  
This might be ugly, since you may have to use different port numbers on the 
wireless, and that might be harder for the other machines on the network.  I 
don't know what you are using the VM for.  If you're using the VM for web 
development, you may want to look into configuring mod_proxy, then you can 
reach the VM over a standard port with a slightly different url.  It's been a 
long time since I've done that myself, but it's pretty easy to setup.


-- 
Thanks:
Joseph Rawson

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