Wrapper for rsync for use with Windows datasets on FreeNAS

#!/bin/bash
#######################################################################
# A wrapper for invoking rsync to copy a source dataset to a destination
# dataset with options that are 'known to work' with FreeNAS/FreeBSD
# and Windows datasets. This means we have to avoid the '-p' (preserve
# permissions) option in all of its forms, per bug report 7713:
#
# https://bugs.freenas.org/issues/7713
#
# Command-line parameters:
#   1: Source dataset       R_SRC     (local system)  /mnt/tank/sharename/
#   2: Destination dataset  R_DEST    (local system)  /volume1/sharename
#   3: Log file             R_LOGFILE (local system)  /mnt/tank/sysadmin/log/push-log.log
#
# R_SRC or R_DEST may include user ID and hostname specifier
#
# Example usage, where 'boomer' is a FreeNAS server and 'bertrand' is
# a Synology Diskstation. Note that you should include a trailing slash
# only on the source dataset specifier:
#
# rsync-invoke.sh root@bertrand:/volume1/devtools/ /mnt/tank/devtools /mnt/tank/sysadmin/log/pull-from-bertrand.log
# rsync-invoke.sh /mnt/tank/devtools/ root@bertrand:/volume1/devtools /mnt/tank/sysadmin/log/push-to-bertrand.log
#
# Assumes SSH has been enabled and configured between the source
# and destination hosts.
#
# Invokes rsync with these SSH options to optimize transfer speed:
#
#   "-e ssh -T -c arcfour -o Compression=no -x"
#
# You may need to remove this altogether, or modify the encryption
# specifier (-c arcfour) to use a scheme available on your system.
#
# !!! WARNING !!!
# This script deletes files on the destination that don't exist
# on the source! Edit R_OPTIONS below and remove '--delete-during'
# and '--inplace' if you don't want this behavior!
#
# Tested with:
#   FreeNAS 9.3-STABLE
#   FreeNAS 9.10-STABLE
#   Synology DSM 5.x (as destination only)
#######################################################################

if [ $# -ne 3 ]
then
  echo "Error: not enough arguments!"
  echo "Usage is: $0 r_src r_dest r_logfile"
  exit 2
fi

R_SRC=$1
R_DEST=$2
R_LOGFILE=$3

# Options:
#   -r  recurse into directories
#   -l  copy symlinks as symlinks
#   -t  preserve modification times
#   -g  preserve group
#   -o  preserve owner
#   -D  preserve device and special files
#   -h  human readable progress
#   -v  increase verbosity

#   --delete-during   receiver deletes during the transfer
#   --inplace         write updated data directly to destination file
#   --log-file        specify log file

R_OPTIONS="-rltgoDhv --delete-during --inplace --log-file="${R_LOGFILE}

# Files to exclude:
#   .windows      FreeNAS ACL settings (?)
#   vmware.log    VMware virtual machine log files
#   vmware-*.log
#   @eaDir/       Synology extended attributes (?)
#   @eaDir
#   Thumbs.db     Windows system files

R_EXCLUDE="--exclude .windows --exclude vmware.log --exclude vmware-*.log --exclude @eaDir/ --exclude @eaDir --exclude Thumbs.db"

echo "$(date) Copy" ${R_SRC} "to" ${R_DEST} >> ${R_LOGFILE}
rsync ${R_OPTIONS} ${R_EXCLUDE} "-e ssh -T -c arcfour -o Compression=no -x" ${R_SRC} ${R_DEST}
echo "$(date) Copy completed" >> ${R_LOGFILE}
exit