prsync

#!/bin/bash

# Original Source: https://wiki.ncsa.illinois.edu/display/~wglick/Parallel+Rsync

DRYRUN=0
VERBOSE=0
THREADS=8

while getopts "s:d:t:vn" opt; do
  case $opt in
    s)
      SRCDIR=$OPTARG
      ;;
    d)
      DESTDIR=$OPTARG
      ;;
    t)
      THREADS=$OPTARG
      ;;
    n)
      DRYRUN=1
      ;;
    v)
      VERBOSE=1
      ;;
    h|help)
      echo "Usage: $0 [s|d|t]"
      exit 1
      ;;
    *)
      echo "Usage: $0 [s|d|t]"
      exit 1
  esac
done

if [ $VERBOSE -eq 1 ]; then
  echo "SRCDIR: $SRCDIR"
  echo "DESTDIR: $DESTDIR"
  echo "THREADS: $THREADS"
fi

# RSYNC DIRECTORY STRUCTURE
if [ $DRYRUN -eq 1 ]; then
  echo "rsync -vr -f"+ */" -f"- *" $SRCDIR/ $DESTDIR/"
else
  rsync -vr -f"+ */" -f"- *" $SRCDIR/ $DESTDIR/
fi

# FOLLOWING MAYBE FASTER BUT NOT AS FLEXIBLE
# cd $SRCDIR; find . -type d -print0 | cpio -0pdm $DESTDIR/

# FIND ALL FILES AND PASS THEM TO MULTIPLE RSYNC PROCESSES
if [ $DRYRUN -eq 1 ]; then
  echo "cd $SRCDIR; find . ! -type d -print0 | xargs -0 -n1 -P$THREADS -I% rsync -av % $DESTDIR/% "
else
  cd $SRCDIR; find . ! -type d -print0 | xargs -0 -n1 -P$THREADS -I% rsync -av --no-g % $DESTDIR/%
fi

# IF YOU WANT TO LIMIT THE IO PRIORITY, 
# PREPEND THE FOLLOWING TO THE rsync & cd/find COMMANDS ABOVE:
# ionice -c2