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PXE (Preboot eXecution Environment)

Environment

Field Spec or Version
CPU QEMU Virtual CPU version 2.5+ (2 Cores)
RAM 2G
OS Rocky Linux 10.0 (Red Quartz)
Network interface ens18 with static IP 192.168.3.11/24
DNS 192.168.3.1 (Private DNS Server)

Package Installation

dnf install -y syslinux syslinux-tftpboot dnsmasq nfs-utils exportfs rsync

Package Configuration

  • Mount Ubuntu Live Iso

    export ISO_MP='/media/iso'
mkdir -p "$ISO_MP"
mount /dev/sr0 "$ISO_MP"

  • /etc/dnsmasq.conf

    # Listen on this specific port instead of the standard DNS port
# (53). Setting this to zero completely disables DNS function,
# leaving only DHCP and/or TFTP.
port=0

# If you want dnsmasq to listen for DHCP and DNS requests only on
# specified interfaces (and the loopback) give the name of the
# interface (eg eth0) here.
# Repeat the line for more than one interface.
interface=ens18

# Uncomment this to enable the integrated DHCP server, you need
# to supply the range of addresses available for lease and optionally
# a lease time. If you have more than one network, you will need to
# repeat this for each network on which you want to supply DHCP
# service.
dhcp-range=192.168.3.200,192.168.3.250,12h

# Override the default route supplied by dnsmasq, which assumes the
# router is the same machine as the one running dnsmasq.
# Do the same thing, but using the option name
dhcp-option=option:router,192.168.3.1
dhcp-option=option:dns-server,192.168.3.1

# Set the boot filename for netboot/PXE. You will only need
# this if you want to boot machines over the network and you will need
# a TFTP server; either dnsmasq's built-in TFTP server or an
# external one. (See below for how to enable the TFTP server.)
dhcp-boot=syslinux.efi

# Enable dnsmasq's built-in TFTP server
enable-tftp

# Set the root directory for files available via FTP.
tftp-root=/var/tftp

# Log lots of extra information about DHCP transactions.
log-dhcp

  • Init TFTP server provided by dnsmasq

    TFTP only provides basic files for PXE, like bootloader, boot menu, and initrd entry.

    export TFTP_PATH='/var/tftp'
mkdir -p "$TFTP_PATH"

# PXE bootloader
cp /tftpboot/efi64/syslinux.efi "$TFTP_PATH"
cp /tftpboot/efi64/ldlinux.e64 "$TFTP_PATH"

# PXE boot menu
mkdir "$TFTP_PATH/pxelinux.cfg"
cat > "$TFTP_PATH/pxelinux.cfg/default" <<'EOF'
DEFAULT ubuntu

LABEL ubuntu
  KERNEL ubuntu/vmlinuz
  INITRD ubuntu/initrd
  APPEND boot=casper netboot=nfs nfsroot=192.168.3.11:/srv/ubuntu-live ip=dhcp ---

EOF

# PXE boot option1 - Ubuntu
export TFTP_UBUNTU_PATH="$TFTP_PATH/ubuntu"
mkdir -p "$TFTP_UBUNTU_PATH"
cp "$ISO_MP/casper/initrd" "$TFTP_UBUNTU_PATH"
cp "$ISO_MP/casper/vmlinuz" "$TFTP_UBUNTU_PATH"

chown -R dnsmasq: "$TFTP_PATH"
chcon -R -t tftpdir_t "$TFTP_PATH"

  • Init NFS server

    NFS provides actual live OS because OS files is too large to TFTP for transfer. TFTP only transfer files with max size about 100M stably.

    export NFS_UBUNTU_PATH='/srv/ubuntu-live'
mkdir -p "$NFS_UBUNTU_PATH"
rsync -a "$ISO_MP/" "$NFS_UBUNTU_PATH/"
chcon -R -t nfs_t "$NFS_UBUNTU_PATH"

cat >> /etc/exports <<EOF
$NFS_UBUNTU_PATH *(ro,sync,no_subtree_check)
EOF

  • Unmount Ubuntu Live Iso

    umount "$ISO_MP"
rmdir "$ISO_MP"

Service Restart

firewall-cmd --permanent --add-service=dhcp
firewall-cmd --permanent --add-service=tftp
firewall-cmd --permanent --add-service=nfs
firewall-cmd --permanent --add-service=rpc-bind
firewall-cmd --permanent --add-service=mountd
firewall-cmd --reload

systemctl enable --now dnsmasq
systemctl restart dnsmasq

exportfs -ra
systemctl enable --now nfs-server
systemctl restart nfs-server
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