ddrescue-loop.sh

#!/bin/sh
# NB: Must run with -1 for until full first pass is complete
firstrun=
sleep=$(( 60 * 60 * 6 )) # 6h
#?sleep=300 # 5m
while getopts 1hs: flag; do
        case "$flag" in
        1) firstrun=1 ;;
        s) sleep="$OPTARG" ;;
        *) echo "$0 [-1h] [from [to [log]]]" >&2
           exit 1
        esac
done
shift $(( $OPTIND - 1 ))
: "${from:=${1:-/dev/ada1}}"
: "${to:=${2:-/dev/ada2}}"
: "${log:=${3:-Recovery.log}}"
n=0
set -e
while :; do
        set -- -f -v -v -n -r1
        n=$(( $n + 1 ))
        if [ "$firstrun" ]; then
                set -- "$@" -a 1048576
        elif [ $(( $n % 2 )) -eq 0 ]; then
                set -- "$@" -M -R -C
#?              set -- "$@" -R -C
        else
                set -- "$@" -M -C
#?              set -- "$@" -C
        fi
        set -- ddrescue "$@" -d "$from" "$to" "$log"
        date
        echo "$@"
        time "$@"
        sleep $sleep
        date | tee -a "$log.loop"
        diff -pu "$log.bak" "$log" | tee -a "$log.loop"
        cp "$log" "$log.bak"
        firstrun=
done