This is the script I used while working at EZSitemove.com to backup customers accounts.
#!/bin/bash
#
# Usage: RSyncSnapshot Source_Directory Target_Directory Number_of_Snapshots_to_Keep
# Log_File
# ----- RSync Options -----
# Explanation of default options
# a = archive mode; equals rlptgoD
# r = recurse into directories
# l = copy symlinks as symlinks
# p = preserve permissions
# t = preserve modification times
# g = preserve group
# o = preserve owner
# D = preserve device and special files
# c = skip based on checksum, not mod-time & size
# v = increase verbosity
# x = don't cross filesystem boundaries
# H = preserve hard links
# S = handle sparse files efficiently
RSYNC_OPTIONS='-acvxHS'
# ----- Prepare Commands -----
# Uncomment the following section if running on FreeNAS and comment the next section
ECHO=/bin/echo
TEST=/bin/[
SLEEP=/bin/sleep
RM=/bin/rm
EXPR=/bin/expr
MV=/bin/mv
RSYNC=/usr/local/bin/rsync
TOUCH=/usr/bin/touch
# Uncomment the following section if running on Ubuntu and comment the previous section, I don't know why Unbuntu has to change things.
# ECHO=/bin/echo
# TEST=[
# SLEEP=/bin/sleep
# RM=/bin/rm
# EXPR=/usr/bin/expr
# MV=/bin/mv
# RSYNC=/usr/bin/rsync
# TOUCH=/bin/touch
# ----- Initialize Variables -----
SOURCE=$1
TARGET=$2
SNAPSHOT_COUNT=$3
LOG_FILE=$4
LOCK_FILE='/mnt/.RSyncSnapshotLock'
RSYNC_LOG_FILE="--log-file=$LOG_FILE"
RSYNC_LINK_TARGET=
# ----- Script -----
# make things a bit more readable when we start echoing stuff
$ECHO
# make sure passed variables make sense
if $TEST ! "$SOURCE" ]
then
$ECHO "Usage: RSyncSnapshot Source_Directory Target_Directory"
$ECHO " Number_of_Snapshots_to_Keep Optional_RSync_Option"
$ECHO " Optional_RSync_Option Optional_RSync_Option"
$ECHO
$ECHO "No source directory specified."
$ECHO
exit 1
fi
if $TEST ! -d "$SOURCE" ]
then
$ECHO "Specified source directory (\"$SOURCE\") doesn't exist."
$ECHO
exit 1
fi
if $TEST ! "$TARGET" ]
then
$ECHO "Usage: RSyncSnapshot Source_Directory Target_Directory"
$ECHO " Number_of_Snapshots_to_Keep Optional_RSync_Option"
$ECHO " Optional_RSync_Option Optional_RSync_Option"
$ECHO
$ECHO "No target directory specified."
$ECHO
exit 1
fi
if $TEST ! -d "$TARGET" ]
then
$ECHO "Specified target directory (\"$TARGET\") doesn't exist."
$ECHO
exit 1
fi
if $TEST ! $SNAPSHOT_COUNT ]
then
$ECHO "Usage: RSyncSnapshot Source_Directory Target_Directory"
$ECHO " Number_of_Snapshots_to_Keep Optional_RSync_Option"
$ECHO " Optional_RSync_Option Optional_RSync_Option"
$ECHO
$ECHO "Number of snapshots to keep not specified."
$ECHO
exit 1
fi
if $TEST "`$EXPR $SNAPSHOT_COUNT - $SNAPSHOT_COUNT 2> /dev/null`" != "0" ]
then
$ECHO "Specified number of snapshots to keep has to be a numeric value."
$ECHO
exit 1
fi
if $TEST $SNAPSHOT_COUNT -lt 1 ]
then
$ECHO "Specified number of snapshots to keep can not be less than one."
$ECHO
exit 1
fi
# make sure no other instance of this script is running
(set noclobber; : > "$LOCK_FILE") 2> /dev/null
if $TEST $? != "0" ]
then
$ECHO "Another instance of the RSyncSnapshot script is already running."
$ECHO "Press Ctrl+C to cancel this script or if no other copy of RSnapshot"
$ECHO "is actually running delete the \"$LOCK_FILE\" file."
$ECHO
$ECHO -n "Waiting for the other instance of RSyncSnapshot to finish ..."
$ECHO "RSyncSnapshot: Waiting for another instance of RSyncSnapshot to finish." \
>> "$LOG_FILE"
# check every 15 seconds if the other instance is done
$SLEEP 15
(set noclobber; : > "$LOCK_FILE") 2> /dev/null
while $TEST $? != "0" ]
do
$ECHO -n "."
$SLEEP 15
(set noclobber; : > "$LOCK_FILE") 2> /dev/null
done
# make things pretty
$ECHO
$ECHO
fi
# delete oldest snapshot if it exists
if $TEST -e "$TARGET/Snapshot.$SNAPSHOT_COUNT" ]
then
$ECHO "Removing oldest snapshot (number $SNAPSHOT_COUNT) ..."
$ECHO "RSyncSnapshot: Removing oldest snapshot (number $SNAPSHOT_COUNT)." \
>> "$LOG_FILE"
$RM -rf "$TARGET/Snapshot.$SNAPSHOT_COUNT"
else
$ECHO "Oldest snapshot (number $SNAPSHOT_COUNT) doesn't exist."
$ECHO "RSyncSnapshot: Oldest snapshot (number $SNAPSHOT_COUNT) doesn't exist." \
>> "$LOG_FILE"
fi
# make each snapshot one snapshot older
while $TEST $SNAPSHOT_COUNT -gt 0 ]
do
# reduce SNAPSHOP_COUNT by 1 (since we've already dealt with one snapshot above)
let SNAPSHOT_COUNT=$SNAPSHOT_COUNT-1
# check if the snapshot might be a file instead of a directory since
# this happens when rsync failed to run correctly the last time
if $TEST -f "$TARGET/Snapshot.$SNAPSHOT_COUNT" ]
then
$ECHO "Removing invalid snapshot (number $SNAPSHOT_COUNT) ..."
$ECHO "RSyncSnapshot: Removing invalid snapshot (number $SNAPSHOT_COUNT)." \
>> "$LOG_FILE"
$RM -f "$TARGET/Snapshot.$SNAPSHOT_COUNT"
else
# check if it's a directory
if $TEST -d "$TARGET/Snapshot.$SNAPSHOT_COUNT" ]
then
$ECHO "Moving snapshot number $SNAPSHOT_COUNT to `$EXPR $SNAPSHOT_COUNT + 1` ..."
$ECHO "RSyncSnapshot: Moving snapshot number $SNAPSHOT_COUNT to `$EXPR \
$SNAPSHOT_COUNT + 1`." \
>> "$LOG_FILE"
$MV "$TARGET/Snapshot.$SNAPSHOT_COUNT" "$TARGET/Snapshot.`$EXPR $SNAPSHOT_COUNT + 1`"
# do the following if it doesn't exist at all
else
$ECHO "Snapshot number $SNAPSHOT_COUNT doesn't exist."
$ECHO "RSyncSnapshot: Snapshot number $SNAPSHOT_COUNT doesn't exist." \
>> "$LOG_FILE"
fi
fi
done
# see if the directory we wanna link to exists already
if $TEST -d "$TARGET/Snapshot.1" ]
then
RSYNC_LINK_TARGET='--link-dest=../Snapshot.1'
fi
# do the actual backup using rsync
$ECHO "Backing up \"$SOURCE\" to snapshot number 0 using the command below ..."
$ECHO "$RSYNC $RSYNC_OPTIONS $RSYNC_LINK_TARGET \\"
$ECHO "\"$RSYNC_LOG_FILE\" \"$SOURCE\" \"$TARGET/Snapshot.0\""
$ECHO
$ECHO "RSyncSnapshot: Backing up \"$SOURCE\" to snapshot number 0 using the command below:" \
>> "$LOG_FILE"
$ECHO "RSyncSnapshot: $RSYNC $RSYNC_OPTIONS $RSYNC_LINK_TARGET \\" \
>> "$LOG_FILE"
$ECHO "RSyncSnapshot: \"$RSYNC_LOG_FILE\" \"$SOURCE\" \"$TARGET/Snapshot.0\"" \
>> "$LOG_FILE"
$RSYNC $RSYNC_OPTIONS $RSYNC_LINK_TARGET "$RSYNC_LOG_FILE" "$SOURCE" "$TARGET/Snapshot.0"
# update the time of the snapshot directory
$TOUCH "$TARGET/Snapshot.0"
# remove lock file
$RM -f "$LOCK_FILE"
# make things pretty
$ECHO
# all done
exit 0