= Ubuntu Server installs = There used to be minimal installers and a python commandline utility to build KVM images. Not Enterprise enough, I suppose. There is still a minimal ISO, hidden away: * 20.04: http://archive.ubuntu.com/ubuntu/dists/focal/main/installer-amd64/current/legacy-images/netboot/mini.iso = Notes on chroot'ing from SystemRescueCD = Say you mount like so: ``` sudo mount /dev/sda1 /mnt sudo mount --bind /dev /mnt/dev && sudo mount --bind /dev/pts /mnt/dev/pts && sudo mount --bind /proc /mnt/proc && sudo mount --bind /sys /mnt/sys sudo chroot /mnt ``` But then running `grub-install` returns ``` grub-install: warning: EFI variables cannot be set on this system. grub-install: warning: You will have to complete the GRUB setup manually. ``` You just need to run `grub-install --removable` to avoid that, having bootstrapped into this via EFI USB boot was how I got there myself certainly as per https://superuser.com/a/1749282

= Ubuntu Server installs = == Minimal installers == There used to be minimal installers and a python commandline utility to build KVM images. Not Enterprise enough, I suppose. There is still a minimal ISO, hidden away: * 20.04: http://archive.ubuntu.com/ubuntu/dists/focal/main/installer-amd64/current/legacy-images/netboot/mini.iso * 22.04: Follow https://www.server-world.info/en/note?os=Ubuntu_22.04 I guess? While the upstream `virt-install` command can create VMs from ubuntu dist trees, there don't seem to be any for 24.04 Noble... Official instructions for netbooting at at https://discourse.ubuntu.com/t/netbooting-the-live-server-installer/14510 lol == Hide ESM rambling == `sudo touch /var/lib/update-notifier/hide-esm-in-motd` as per https://askubuntu.com/a/1509911/306954 (may also need to run `sudo rm /var/lib/update-notifier/updates-available`?). = Notes on chroot'ing from SystemRescueCD or the like = You can mount it like so: ``` lang=bash # Mounting a classic MBR/Legacy install sudo mount /dev/sda1 /mnt # Or, mounting a UEFI install, you may find the first partition is actually an EFI partition rather than your root. So instead it's more like: sudo mount /dev/sda2 /mnt sudo mount /dev/sda1 /mnt/boot/efi # Either way, then mount all the devices from the live session sudo mount --bind /dev /mnt/dev sudo mount --bind /dev/pts /mnt/dev/pts sudo mount --bind /proc /mnt/proc sudo mount --bind /sys /mnt/sys # And now chroot into a shell in your existing install sudo chroot /mnt ``` But if you're fixing GRUB on an EFI system and have booted into SystemRescueCD (or a live Kubuntu USB or such) in UEFI mode you may then find that running `grub-install` returns ``` grub-install: warning: EFI variables cannot be set on this system. grub-install: warning: You will have to complete the GRUB setup manually. ``` You just need to run `grub-install --removable` to avoid that, having bootstrapped into this via EFI USB boot was how I got there myself certainly as per https://superuser.com/a/1749282 = Hey I have an old 18.04 32-bit install and I wanna bitness crossgrade because reinstallers are cowards = See https://wiki.debian.org/CrossGrading, which builds on https://wiki.debian.org/Multiarch/HOWTO, but I did specifically the following to go from i386 to amd64: # `dpkg --add-architecture amd64` # `apt update` # `apt install linux-generic:amd64` (rather than `linux-image-amd64:amd64`) # `reboot` # `apt clean` to ensure laziness isn't punished later # `apt install libbz2-1.0:amd64 libacl1:amd64 liblzma5:amd64 libgcrypt20:amd64 libsystemd0:amd64 libselinux1:amd64 libzstd1:amd64` for some additional packages needed before... # `apt --download-only install dpkg:amd64 tar:amd64 apt:amd64 ` ## and hey maybe also `apt --download-only install --reinstall dpkg:i386 tar:i386 apt:i386` if you want those around for when the attempted 64-bit install of the package manager fails # `dpkg --install /var/cache/apt/archives/*_amd64.deb` # `dpkg --print-architecture` should now return `amd64` (and, like, not crash or anything) # `apt purge '?obsolete'` is recommended by the Debian instructions, didn't need it myself # Now run: ## `apt-mark showauto | sed -n -e's/:i386$//p' > auto-package-list` ## `apt install $(dpkg -l | awk '$1 ~ /^.i/ && $2 ~ /:i386$/ { sub(":i386", ""); print $2 }')` ## `xargs apt-mark auto < auto-package-list` # That results in a state where you now will need to run `apt --fix-broken install` and hopefully the gods are on your side---apparently they're on mine!

= Ubuntu Server installs = == Minimal installers == There used to be minimal installers and a python commandline utility to build KVM images. Not Enterprise enough, I suppose. There is still a minimal ISO, hidden away: * 20.04: http://archive.ubuntu.com/ubuntu/dists/focal/main/installer-amd64/current/legacy-images/netboot/mini.iso * 22.04: Follow https://www.server-world.info/en/note?os=Ubuntu_22.04 I guess? While the upstream `virt-install` command can create VMs from ubuntu dist trees, there don't seem to be any for 24.04 Noble... Official instructions for netbooting at at https://discourse.ubuntu.com/t/netbooting-the-live-server-installer/14510 lol == Hide ESM rambling == `sudo touch /var/lib/update-notifier/hide-esm-in-motd` as per https://askubuntu.com/a/1509911/306954 (may also need to run `sudo rm /var/lib/update-notifier/updates-available`?). = Notes on chroot'ing from SystemRescueCD or the like = Say youYou can mount it like so: ``` lang=bash # Mounting a classic MBR/Legacy install sudo mount /dev/sda1 /mnt sudo mount --bind /dev /mnt/dev &&# Or, mounting a UEFI install, you may find the first partition is actually an EFI partition rather than your root. So instead it's more like: sudo mount --bind /dev/ptssda2 /mnt/dev/pts &&t sudo mount --bind /proc /mnt/proc &&/dev/sda1 /mnt/boot/efi # Either way, then mount all the devices from the live session sudo mount --bind /dev /mnt/dev sudo mount --bind /dev/pts /mnt/dev/pts sudo mount --bind /proc /mnt/proc sudo mount --bind /sys /mnt/sys # And now chroot into a shell in your existing install sudo chroot /mnt ``` But thenif you're fixing GRUB on an EFI system and have booted into SystemRescueCD (or a live Kubuntu USB or such) in UEFI mode you may then find that running `grub-install` returns ``` grub-install: warning: EFI variables cannot be set on this system. grub-install: warning: You will have to complete the GRUB setup manually. ``` You just need to run `grub-install --removable` to avoid that, having bootstrapped into this via EFI USB boot was how I got there myself certainly as per https://superuser.com/a/1749282 = Hey I have an old 18.04 32-bit install and I wanna bitness crossgrade because reinstallers are cowards = See https://wiki.debian.org/CrossGrading, which builds on https://wiki.debian.org/Multiarch/HOWTO, but I did specifically the following to go from i386 to amd64: # `dpkg --add-architecture amd64` # `apt update` # `apt install linux-generic:amd64` (rather than `linux-image-amd64:amd64`) # `reboot` # `apt clean` to ensure laziness isn't punished later # `apt install libbz2-1.0:amd64 libacl1:amd64 liblzma5:amd64 libgcrypt20:amd64 libsystemd0:amd64 libselinux1:amd64 libzstd1:amd64` for some additional packages needed before... # `apt --download-only install dpkg:amd64 tar:amd64 apt:amd64 ` ## and hey maybe also `apt --download-only install --reinstall dpkg:i386 tar:i386 apt:i386` if you want those around for when the attempted 64-bit install of the package manager fails # `dpkg --install /var/cache/apt/archives/*_amd64.deb` # `dpkg --print-architecture` should now return `amd64` (and, like, not crash or anything) # `apt purge '?obsolete'` is recommended by the Debian instructions, didn't need it myself # Now run: ## `apt-mark showauto | sed -n -e's/:i386$//p' > auto-package-list` ## `apt install $(dpkg -l | awk '$1 ~ /^.i/ && $2 ~ /:i386$/ { sub(":i386", ""); print $2 }')` ## `xargs apt-mark auto < auto-package-list` # That results in a state where you now will need to run `apt --fix-broken install` and hopefully the gods are on your side---apparently they're on mine!