incbak-root.sh

#!/bin/bash

blue='\e[0;34m'
red='\e[0;31m'
NC='\e[0m'

BTRFS_ROOT="/mnt/btrfs"
NUM_TO_KEEP=7

new_name=$(date +root_%Y-%m-%d_%T)

echo -e "${blue}Taking rw 'last' snapshot of root:${NC}"
btrfs subvolume snapshot ${BTRFS_ROOT}/root ${BTRFS_ROOT}/root-last-new
btrfs subvolume delete ${BTRFS_ROOT}/root-last
mv ${BTRFS_ROOT}/root-last-new ${BTRFS_ROOT}/root-last
cp /boot/vmlinuz-linux /boot/vmlinuz-linux-last
cp /boot/initramfs-linux-fallback.img /boot/initramfs-linux-last-fallback.img
sed -i 's|subvol=root|subvol=root-last|' ${BTRFS_ROOT}/root-last/etc/fstab

echo -e "${blue}Taking ro snapshot of root: ${new_name}${NC}"
btrfs subvolume snapshot -r ${BTRFS_ROOT}/root ${BTRFS_ROOT}/${new_name}

echo -e "${blue}Removing old snapshots${NC}"
for snapshot in $(ls ${BTRFS_ROOT} | grep root_ | sort | head -n -"${NUM_TO_KEEP}"); do
    echo -e "Removing ${snapshot}"
    btrfs subvolume delete ${BTRFS_ROOT}/${snapshot}
done