256GB.

Pick a size, copy the script, paste it into your terminal.

#!/usr/bin/env bash
set -euo pipefail

SIZE_GB=256
SWAPFILE=/swapfile

sudo fallocate -l "${SIZE_GB}G" "$SWAPFILE" \
  || sudo dd if=/dev/zero of="$SWAPFILE" bs=1M count=$((SIZE_GB * 1024)) status=progress
sudo chmod 600 "$SWAPFILE"
sudo mkswap "$SWAPFILE"
sudo swapon "$SWAPFILE"

grep -q "^$SWAPFILE " /etc/fstab \
  || echo "$SWAPFILE none swap sw 0 0" | sudo tee -a /etc/fstab >/dev/null

swapon --show