Solved Ubuntu Live Boot Booting to Disk Install Not Live CD

[foggystarz]

Hi, I have followed @george1421’s excellent guide to setup booting a Ubuntu 20.03 image which is working, but for some reason it’s not booting to Live CD. When booting the VM it goes straight to the install on disk procedure. I did google around but most of the links relate to older versions with a different netboot (vmlinux instead of linux), I’ve added the boot=live argument as per below which doesn’t seem to do anything, anyone know the answer to this?

kernel tftp://${fog-ip}/os/ubuntu/live20.04/linux
initrd tftp://${fog-ip}/os/ubuntu/live20.04/initrd.gz
imgargs linux boot=live root=/dev/nfs boot=casper netboot=nfs nfsroot=${fog-ip}:/images/os/ubuntu/live20.04/ locale=en_US.UTF-8 keyboard-configuration/layoutcode=us quiet splash ip=dhcp rw
boot || goto MENU

Many thanks for any help,
Will

[foggystarz]

@george1421 I think I follow, I’ll give it a bash and let you know, thank you :).

[george1421]

@foggystarz TBH I don’t know. If it was me I’d copy them to the fog server in a different directory than the one you have working and try just the cdrom initrd file (keep the network kernel one from the working [linux] ) and try to boot. See where you end up.

See the linux has the NFS services turned on where the vmlinuz one probably doesn’t. What you need (maybe) is the logic in the virtual hard drive [initrd] to start up the live runtime and not the installer.

[foggystarz]

@george1421 So in theory all I need to do is copy those files from a ubuntu install to the tftp folder on the fog host?

[foggystarz]

@Sebastian-Roth Yes when I was googling around attempting to figure out the issue I came across the vmlinuz boot a lot but assumed it was part of older distros as couldn’t find any newish posts. I think you’re on to something here too.

[george1421]

@Sebastian-Roth said in Ubuntu Live Boot Booting to Disk Install Not Live CD:

label live
menu label ^Try Ubuntu without installing
kernel /casper/vmlinuz
append file=/cdrom/preseed/ubuntu.seed initrd=/casper/initrd quiet splash —
…

You may have hit on the problem/solution. Per the tutorial the kernel and initrd comes from a download and not the ISO image. The try-ubuntu option may only be accessible using those files. I probably would start with the casper/initrd file.

wget http://archive.ubuntu.com/ubuntu/dists/eoan/main/installer-amd64/current/images/netboot/netboot.tar.gz
tar -zxf netboot.tar.gz
cp ./ubuntu-installer/amd64/linux /tftpboot/os/ubuntu/Server19.10
cp ./ubuntu-installer/amd64/initrd.gz /tftpboot/os/ubuntu/Server19.10

[Sebastian Roth]

@foggystarz I’ve just had a quick look at the bootloader in the Ubuntu 20.04 Desktop ISO file and found the following in isolinux/txt.cfg file:

label live
  menu label ^Try Ubuntu without installing
  kernel /casper/vmlinuz
  append  file=/cdrom/preseed/ubuntu.seed initrd=/casper/initrd quiet splash ---
...

The preseed file does not yield much helpful stuff I reckon. So I am wondering what kernel (files linux / vmlinuz) and initrd (files initrd.gz / initrd) you used?!

The other thing I just noticed is that you don’t use the initrd= kernel parameter. I am not sure what exactly it does but I remember that we had to add this parameter to our FOG boot loading at some stage (kernel version new than X or since UEFI came up??) to make it work properly.

And third, you might want to remove the kernel parameters quiet splash to see more information on screen any maybe spot something that might lead us to understand what’s on.

[Sebastian Roth]

@george1421 said in Ubuntu Live Boot Booting to Disk Install Not Live CD:

if you had the CDROM in front of you, how would you get into the try-ubuntu mode? Is it a grub boot menu selection (option) before the OS boots?

Yes, it’s a boot menu selection. See picture of it here: https://ubuntucommunity.s3.dualstack.us-east-2.amazonaws.com/original/2X/5/5be2cc3620044ff4f6b1f88279accee82efff83d.png

This is what you see when booting the Desktop ISO on a VM or burned to a CD/DVD or USB key.

[george1421]

@foggystarz said in Ubuntu Live Boot Booting to Disk Install Not Live CD:

You say it should boot to installer mode right away, if this is expected how do we pass an argument to enable the menu where you can ‘try ubuntu’?

Ok since I don’t know (like) ubuntu, if you had the CDROM in front of you, how would you get into the try-ubuntu mode? Is it a grub boot menu selection (option) before the OS boots?

[foggystarz]

@george1421 live mode being the live CD options the ubuntu installer gives you when for instance you burn to CD or mount on a USB and boot it. so basically running it in RAM. Through fog currently that menu where you can ‘try ubuntu’ is not available, I guess some boot param makes it skip straight to ‘install to disk’ mode.

As far as I understand it, netboot is running an OS over the network but the storage isn’t local but the OS is still technically installed somewhere else so not related to to this unless I’ve got that wrong?

You say it should boot to installer mode right away, if this is expected how do we pass an argument to enable the menu where you can ‘try ubuntu’?

I don’t know a lot about this stuff so I’m just using this as a practical end-user and I’ve followed the guides to get this up and running, unfortunately, troubleshooting this albeit small issue is well out of my area of understanding, I don’t know how any of this works under the top layer so I can’t help much but I think other people will run in to the same thing as I have as I’ve not done anything bespoke (I wouldn’t know how to :)). I can however load more VM’s/run some tests/arguments if any more ideas, let me know.

[foggystarz]

This post is deleted!

[george1421]

@Sebastian-Roth @foggystarz I guess we need to clarify what is live mode. Is this the installer mode, because it should do that right away, or is this netbooting ubuntu to give the same appearance as if the the system was running from local disk storage?

[Sebastian Roth]

@george1421 Have you been able to boot into live mode with Ubuntu yet? I don’t find the time to play with it these days.

[foggystarz]

@Sebastian-Roth said in Ubuntu Live Boot Booting to Disk Install Not Live CD:

@foggystarz said in Ubuntu Live Boot Booting to Disk Install Not Live CD:

boots straight to Desktop mode

You meant install mode I suppose?!

Yep install mode

[Sebastian Roth]

@foggystarz said in Ubuntu Live Boot Booting to Disk Install Not Live CD:

boots straight to Desktop mode

You meant install mode I suppose?!

[foggystarz]

@Sebastian-Roth Didn’t get round to this last night but just tried Ubuntu 18.04 and same problem, tried both suggested boot arguments boot=live and boot=casper, boots straight to Desktop mode, pictures below:

[foggystarz]

@Sebastian-Roth I’ll do that now bud and report back when tested.

[Sebastian Roth]

@foggystarz Just to make sure this is not something specific to Ubuntu 20.04 - would you setup the same for 18.04 and see if it works as you expect?

[foggystarz]

Thanks @Sebastian-Roth but this also boots to desktop install, I think it may be something to do with netboot files from googling, does this perhaps specify a desktop boot only?

[Sebastian Roth]

@foggystarz Haven’t tried this myself but I found references to using another kernel parameter instead of boot=live (1) try boot=casper (2) a try.