177 lines
		
	
	
		
			4.0 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
			
		
		
	
	
			177 lines
		
	
	
		
			4.0 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
# Installing NixOS in a new node
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This article shows the steps to install NixOS in a node following the
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configuration of the repo.
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## Enable the serial console
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By default, the nodes have the serial console disabled in the GRUB and also boot
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without the serial enabled.
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To enable the serial console in the GRUB, set in /etc/default/grub the following
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lines:
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```
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GRUB_TERMINAL="console serial"
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GRUB_SERIAL_COMMAND="serial --speed=115200 --unit=0 --word=8 --parity=no --stop=1"
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```
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To boot Linux with the serial enabled, so you can see the boot log and login via
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serial set:
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```
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GRUB_CMDLINE_LINUX="console=ttyS0,115200n8 console=tty0"
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```
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Then update the grub config:
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```
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# grub2-mkconfig -o /boot/grub2/grub.cfg
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```
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And reboot.
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## Prepare the disk
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Create a main partition and label it `nixos` following [the manual][1].
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[1]: https://nixos.org/manual/nixos/stable/index.html#sec-installation-manual-partitioning.
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```
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# disk=/dev/sdX
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# parted $disk -- mklabel msdos
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# parted $disk -- mkpart primary 1MB -8GB
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# parted $disk -- mkpart primary linux-swap -8GB 100%
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# parted $disk -- set 1 boot on
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```
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Then create an etx4 filesystem, labeled `nixos` where the system will be
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installed. **Ensure that no other partition has the same label.**
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```
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# mkfs.ext4 -L nixos "${disk}1"
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# mkswap -L swap "${disk}2"
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# mount ${disk}1 /mnt
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# lsblk -f $disk
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NAME   FSTYPE LABEL UUID                                 MOUNTPOINT
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sdX
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`-sdX1 ext4   nixos 10d73b75-809c-4fa3-b99d-4fab2f0d0d8e /mnt
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```
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## Prepare nix and nixos-install
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Mount the nix store from the hut node in read-only /nix.
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```
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# mkdir /nix
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# mount -o ro hut:/nix /nix
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```
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Get the nix binary and nixos-install tool from hut:
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```
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# ssh hut 'readlink -f $(which nix)'
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/nix/store/0sxbaj71c4c4n43qhdxm31f56gjalksw-nix-2.13.3/bin/nix
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# ssh hut 'readlink -f $(which nixos-install)'
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/nix/store/9yq8ps06ysr2pfiwiij39ny56yk3pdcs-nixos-install/bin/nixos-install
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```
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And add them to the PATH:
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```
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# export PATH=$PATH:/nix/store/0sxbaj71c4c4n43qhdxm31f56gjalksw-nix-2.13.3/bin
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# export PATH=$PATH:/nix/store/9yq8ps06ysr2pfiwiij39ny56yk3pdcs-nixos-install/bin/
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# nix --version
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nix (Nix) 2.13.3
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```
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## Adapt owl configuration
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Clone owl repo:
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```
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$ git clone git@bscpm03.bsc.es:rarias/owl.git
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$ cd owl
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```
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Edit the configuration to your needs.
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## Install from another Linux OS
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Install nixOS into the storage drive.
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```
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# nixos-install --flake --root /mnt .#xeon0X
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```
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At this point, the nixOS grub has been installed into the nixos device, which
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is not the default boot device. To keep both the old Linux and NixOS grubs, add
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an entry into the old Linux grub to jump into the new grub.
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```
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# echo "
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menuentry 'NixOS' {
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    insmod chain
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    search --no-floppy --label nixos --set root
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    configfile /boot/grub/grub.cfg
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} " >> /etc/grub.d/40_custom
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```
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Rebuild grub config.
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```
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# grub2-mkconfig -o /boot/grub/grub.cfg
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```
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To boot into NixOS manually, reboot and select NixOS in the grub menu to boot
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into NixOS.
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To temporarily boot into NixOS only on the next reboot run:
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```
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# grub2-reboot 'NixOS'
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```
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To permanently boot into NixOS as the default boot OS, edit `/etc/default/grub/`:
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```
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GRUB_DEFAULT='NixOS'
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```
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And update grub.
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```
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# grub2-mkconfig -o /boot/grub/grub.cfg
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```
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## Build the nixos kexec image
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```
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# nix build .#nixosConfigurations.xeon02.config.system.build.kexecTree -v
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```
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## Chain NixOS in same disk with other systems
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To install NixOS on a partition along another system which controls the GRUB,
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first disable the grub device, so the GRUB is not installed in the disk by
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NixOS (only the /boot files will be generated):
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```
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boot.loader.grub.device = "nodev";
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```
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Then add the following entry to the old GRUB configuration:
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```
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menuentry 'NixOS' {
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        insmod chain
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        search --no-floppy --label nixos --set root
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        configfile /boot/grub/grub.cfg
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}
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```
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The partition with NixOS must have the label "nixos" for it to be found. New
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system configuration entries will be stored in the GRUB configuration managed
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by NixOS, so there is no need to change the old GRUB settings.
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