⑨ lab ≡ ByteLabs

Plan9/Virtualisation

— Igor Böhm

How to create an OpenBSD 6.8 VM on 9front using vmx(1) in 8 minutes

⑨ lab ≡ 9front VMX screencast…

term% @{ramfs ; cd /tmp ; hget https://9lab.org/vid/plan9/9vmx.mp4 > 9vmx.mp4 && treason 9vmx.mp4}

Vmx(1) uses Intel VT-x through vmx(3) to simulate a virtual PC. Using vmx(1) you can run other operating systems as virtual machines on 9front.

Preparation

Make sure you read vmx(3) first to understand how to control a VM. Especially if your host machine does not have a lot of RAM ensure to stop and destroy a virtual CPU after shutting down your VM before starting a new VM instance, otherwise your system will crash.

After shutting down an OpenBSD VM by running halt or some other command and after vmx(1) returns to the terminal, stop the virtual CPU and then destroy it:

term% echo stop >> '#X/0/ctl'
term% echo quit >> '#X/0/ctl'

If the VM disk (assuming it is a file) is stored on a cwfs file system it is advisable to mark it as a temporary file using chmod +t vm.disk to avoid it being dumped to the worm every night. Another approach is to store the VM disk to the other partition that is not backed up.

OpenBSD 6.8 as a VM on 9front

Download

Download 6.8 install media from OpenBSD mirror:

term% mkdir /n/other/usr/$user/vm/bsd/o/amd64
term% cd /n/other/usr/$user/vm/bsd/o/amd64
term% hget https://cdn.openbsd.org/pub/OpenBSD/6.8/amd64/bsd.rd > bsd68.rd
term% hget https://cdn.openbsd.org/pub/OpenBSD/6.8/amd64/bsd > bsd68
term% hget https://cdn.openbsd.org/pub/OpenBSD/6.8/amd64/install68.img > install68.img

Install

Create virtual disk (the example creates a 20G disk):

term% cd /n/other/usr/$user/vm/bsd/o/
term% dd </dev/zero -of obsd.disk -bs 1 -count 1 \
  -seek `{echo 20*1024*1024*1024-1 |pc -n}

Start the installation procedure (NOTE to install the VM use bsd.rd):

term% cat install.rc
#!/bin/rc
ARCH=amd64
OBSD=68

echo stop >> '#X/0/ctl'
echo quit >> '#X/0/ctl'

vmx -M 1G                     \
    -n ether0                 \
    -d obsd.disk              \
    -d $ARCH/install$OBSD.img \
    -v vesa:1600x710          \
    $ARCH/bsd$OBSD.rd

echo stop >> '#X/0/ctl'
echo quit >> '#X/0/ctl'

term% ./install.rc

Checkout the screencast on youtube as an example demonstrating how to chose the install media and other options if in doubt.

Run

After having installed the VM the following script can be used to run it (NOTE to run the VM use bsd):

term% cat $home/bin/rc/vm/start
#!/bin/rc
rfork e
ARCH=amd64
OBSD=68

DISK=/n/other/usr/$user/vm/bsd/o/obsd.disk
BSD=/n/other/usr/$user/vm/bsd/o/$ARCH/bsd$OBSD

fn VmxStop{
	if(test -d '#X/0'){
		echo stop >> '#X/0/ctl'
		sleep 1
		echo quit >> '#X/0/ctl'
		sleep 1
	}
}

fn VmxStart{
	vmx -M 4G             \
		-n ether0         \
		-d $DISK          \
		-v vesa:1600x710  \
		$BSD 'device=sd0a'
}

VmxStop
VmxStart
VmxStop

term% vm/start
…

Good luck! You will need it…

And here is the above screencast on youtube:

#Plan9 #9front