check_disk.sh

#!/bin/sh
#
# This is run by d-i before the partman step (e.g. d-i partman/early_command)

#MIN_DISK_SIZE=20000000

youlose() {
  echo ""
  echo "****************************"
  echo "ERROR: $@"
  echo "Installation cannot proceed. Press any key to reboot."
  read foo
  echo "Rebooting, please wait..."
  reboot
}

# Unmount partitions because partman and d-i are incompetent.
# http://ubuntuforums.org/showthread.php?t=2215103&p=12977473
# LP: 1355845
for p in $(list-devices partition); do
  umount "$p" || true
done


disks=$(list-devices disk)

if ! echo "$disks" | grep -q ^/dev; then
  youlose "No disks found."
fi

for dsk in $disks
do
    echo $dsk  "$(sfdisk -s "$dsk")"
    #if [ "$(sfdisk -s "$dsk")" -lt $MIN_DISK_SIZE ]; then
    #  youlose "Your disk is too small ($(( $MIN_DISK_SIZE / 1000000)) GB required)."
    #fi
done

read -p "Ingrese el disco a usar: " opt

#chvt 5
# Steal STDIN and STDOUT back from the installer
exec < /dev/tty1 > /dev/tty1 2>&1

# Tell partman which disk to use
debconf-set partman-auto/disk "$opt"

exit 0