Rsync 3 script for migrating one Time Machine drive to another

looper.sh

#!/usr/bin/env bash

# Inspired by: http://nicolasgallagher.com/mac-osx-bootable-backup-drive-with-rsync/

# --acls                   update the destination ACLs to be the same as the source ACLs
# --archive                turn on archive mode (recursive copy + retain attributes)
# --delete                 delete any files that have been deleted locally
# --delete-excluded        delete any files (on DST) that are part of the list of excluded files
# --exclude-from           reference a list of files to exclude
# --hard-links             preserve hard-links
# --one-file-system        don't cross device boundaries (ignore mounted volumes)
# --sparse                 handle sparse files efficiently
# --verbose                increase verbosity
# --xattrs                 update the remote extended attributes to be the same as the local ones

# Ask for the administrator password upfront
sudo -v

# IMPORTANT: Make sure you update the `DST` variable to match the name of the
# destination backup drive

SRC="/Volumes/Backup/"
DST="/Volumes/Time Machine/"
PROG=$0

if [ ! -r "$SRC" ]; then
    logger -t $PROG "Source $SRC not readable - Cannot start the sync process"
    exit;
fi

if [ ! -w "$DST" ]; then
    logger -t $PROG "Destination $DST not writeable - Cannot start the sync process"
    exit;
fi

logger -t $PROG "Start rsync"

sudo /usr/local/Cellar/rsync/3.1.2/bin/rsync --acls \
                                             --archive \
                                             --delete \
                                             --hard-links \
                                             --sparse \
                                             --verbose \
                                             --xattrs \
                                             --progress \
                                             "$SRC" "$DST"

logger -t $PROG "End rsync"