Default configuration /etc/mkinitcpio.conf.

The resulting initramfs should be

• small, around 50MiB and below, because a larger file could result in error: timeout reading netboot/initramfs-linux.nfs.img (atftpd.log), ICMP enp0s0.localdomain udp port 46503 unreachable, length 40 (tcpdump), and
• readable otherwise ATFTP returns error File netboot/initramfs-linux.nfs.img not found.

1. Copy the net bash script as net_nfs4 cp /usr/lib/initcpio/install/net /etc/initcpio/install/net_nfs4.
2. Edit /etc/initcpio/install/net_nfs4
   1. -add_module nfsv3?
   2. +add_module nfsv4?
   3. -add_binary "/usr/lib/initcpio/nfsmount" "/bin/nfsmount"
   4. +add_binary "/usr/lib/initcpio/nfsmount" "/bin/mount.nfs4"
3. Copy the net bash script as net_nfs4 cp /usr/lib/initcpio/hooks/net /etc/initcpio/hooks/net_nfs4.
4. Edit /etc/initcpio/hooks/net_nfs4
   1. -nfsmount ${nfs_option:+-o ${nfs_option}} "${nfs_server}:${nfs_path}" "$1"
   2. +mount.nfs4 "${nfs_server}:${nfs_path}" "$1" ${nfs_option:+-o ${nfs_option}}
5. Configure the mkinitcpio.netboot.nfs.conf
   • Auto-detect is necessary to keep the size of the initamfs image low.
   • If building on another hardware than the one to deploy on then auto-detect may exclude the necessary network driver. Therefore, manually add the module to ensure that ipconfig finds the network device.
   1. MODULES=(nfsv4 [module for network device])
   2. BINARIES=(/usr/bin/mount.nfs4)
   3. FILES=()
   4. HOOKS="base udev autodetect net_nfs4 ..."
   5. COMPRESSION="xz"
   6. COMPRESSION_OPTIONS="-9e"
6. Build the new image: mkinitcpio -c <file> -g /netboot/initramfs-linux.nfs.img
7. Ensure that the binaries are embedded in the initamfs:
   1. $ lsinitcpio -a /boot/initramfs-linux.img

The name of the hook must be "net_nfs4". For exemple, the name "net_nfs" causes the mkinitcpio to report:

==> WARNING: Hook 'net_nfs' is deprecated. Replace it with 'net_nfs4' in your config

For debugging purposes, in /usr/lib/initcpio/hooks/net_nfs4 add the following

nfs_mount_handler() {
  if
    ...
  fi
  + echo ""
  + echo "debug> mount.nfs4 ${nfs_server}:${nfs_path} [$1] -v ${nfs_option:+-o ${nfs_option}}"
  + echo ""

  - mount.nfs4 "${nfs_server}:${nfs_path}" "$1" ${nfs_option:+-o ${nfs_option}}
  + mount.nfs4 "${nfs_server}:${nfs_path}" "$1" -v ${nfs_option:+-o ${nfs_option}}

  + sleep 12
}

archlinux efi netboot kernel “ip” does not work?; systemd “Failed to start Switch Root.” -- asked Dec 3 at 2:26 -- user212827