debootstrap-install.markdown

Debian installation using only debootstrap

Prerequisites

A minimal Debian installation on a USB stick in EFI mode.

Using grml would be easier to prepare but only works from legacy (BIOS) boot and does not come with systemd-nspawn.

A future task would be to add statelessness to the USB stick and enable boot to RAM.

Disable udev rules for the USB stick.

Debian will create a file /etc/udev/rules.d/70-persistent-net.rules with whatever the current ethernet addresses are, containing something like

SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="ab:cd:ef:01:03:05", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0

this tells the system to reserve the name eth0 for an ethernet adapter with address ab:cd:ef:01:03:05. Obviously, we want to use the USB stick on other machines as well and we don’t want those other machines to start numbering the ethernet adapters from eth1 on. Let us therefore ensure that Debian won’t ever create the file again:

root@usb-boot:~ $ rm /etc/udev/rules.d/70-persistent-net.rules
root@usb-boot:~ $ touch /etc/udev/rules.d/70-persistent-net.rules

Prepare hard drive

Now reboot the target machine from our USB stick.

Our partitioning scheme shall be as follows:

1. 512 MiB /boot/efi – EFI  – EFI Boot Partition
2. 256 MiB /boot     – ext2 – Boot
3. rest    vg-main   – LVM

vg-main:
   70 GiB /          – xfs  – Root fs
   12 GiB swap       – swap – Swap
   rest   /extra     – xfs  – User writable area

We can automate the partitioning with sgdisk and the LVM tools.

PARTITION=/dev/sda ## Change as needed!

echo "Current partition layout on ${PARTITION} is:"
sgdisk -p $PARTITION

echo "Deleting all data. Press button or quit with CTRL-C"
read

sgdisk -Z $PARTITION
sgdisk --new=1:0:+512M --typecode=1:EF00 --change-name=1:"EFI Boot" $PARTITION
sgdisk --new=2:0:+256M --typecode=2:8300 --change-name=2:"Boot" $PARTITION
sgdisk --new=3:0:0     --typecode=3:8E00 --change-name=3:"LVM" $PARTITION

vgcreate vg-main ${PARTITION}3
lvcreate vg-main --size +70G --name root
lvcreate vg-main --size +12G --name swap
lvcreate vg-main --extents 100%FREE --name extra

mkfs.vfat -F 32 ${PARTITION}1
mkfs.ext2 ${PARTITION}2

mkfs.xfs /dev/vg-main/root
mkswap /dev/vg-main/swap
mkfs.xfs /dev/vg-main/extra

Mount the target

mkdir -p /target
mount /dev/vg-main/root /target
mkdir -p /target/boot
mount ${PARTITION}2 /target/boot
mkdir -p /target/boot/efi
mount ${PARTITION}1 /target/boot/efi
mkdir -p /target/extra

debootstrap --arch amd64 jessie /target http://apt-cacher-ng.local.pri:3142/ftp.de.debian.org/debian
# alternatively
# debootstrap --arch amd64 jessie /target http:/ftp.de.debian.org/debian

sed -i -e s/main/"main contrib non-free"/g /target/etc/apt/sources.list
mount -o bind /dev /target/dev
mount -o bind /dev/shm /target/dev/shm
mount -o bind /proc /target/proc
mount -o bind /sys /target/sys
mount -t devpts devpts /target/dev/pts

chroot /target /usr/bin/apt-get update
chroot /target /usr/bin/apt-get install -y lvm2 xfsprogs linux-image-amd64 grub-efi-amd64 firmware-linux

# Create fstab

cat >> /target/etc/fstab <<EOF
# /etc/fstab: static file system information.
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
UUID=$( blkid -s UUID -o value ${PARTITION}1 ) /boot/efi vfat umask=0077 0 1
UUID=$( blkid -s UUID -o value ${PARTITION}2 ) /boot ext2 defaults 0 2
/dev/mapper/vg--main-root / xfs defaults 0 2
/dev/mapper/vg--main-swap none swap sw 0 0
/dev/mapper/vg--main-extra /extra xfs defaults 0 1
EOF