Rsnap - do periodic incremental snapshots using Rsync and ls4sweep.

rsnap.sh

#!/bin/sh

Fail() {
	logger -p "user.err" -t "rsnap" -s "$@";
	#echo "$@" | mail -s "rsnap failed on $(hostname -f)" admins
	exit 1
}


#======   Parse command line   =================================

test $# -ge 2 || Fail "usage: $0 src destdir [custom-rsync-args..]"
     src="$1"; shift
destbase="$1"; shift

test -e "$destbase/" || Fail "missing directory $destbase"


#======   Prepare logdir   =====================================

now="$(date +%Y-%m-%d_%H%M)"
logdir="$destbase/logs"
mkdir -p "$logdir"
test -d "$logdir" || Fail "cannot create logdir $logdir"


#======   Check previous snapshot   ============================

prevsnap="$destbase/last"
prevopt=""
if test -e "$prevsnap"; then
	test -L "$prevsnap" || Fail "$prevsnap exists, but is not symlink"
	prevopt="--link-dest=$prevsnap"
fi


#======   Prepare for new snapshot   ===========================

newsnap="$destbase/$now"
mkdir "$newsnap"  || Fail "mkdir $newsnap"
cd    "$newsnap/" || Fail "chdir $newsnap"


#======   Do rsync   ===========================================

L="$logdir/$now-rsync.log"
E="$logdir/$now-rsync.err"
if ! rsync -auxXSH --stats --delete --numeric-ids "$@" $prevopt "$src/" . > "$L" 2>"$E"; then
	mv "$newsnap" "$newsnap.failed"
	Fail "rsync failed, see $E"
fi

# Rebind symlink..
cd "$destbase"
rm -f "last"
ln -s "$now" "last"


#======   Delete old snapshots   ===============================

sweep_policy="5:1,5:3,5:10,15:30,15:90,15:360,99:1000"
sweep_mask='????-??-??_????'  # ..see $now assignment above!!
L1="$logdir/$now-sweep.log"
E1="$logdir/$now-sweep.err"
E2="$logdir/$now-rm.err"

test "$DONT_SWEEP" = "1" ||
ls4sweep --ctime "$sweep_policy" $sweep_mask 2>"$E1" |
  grep -v "^$now$" | tee "$L1" | xargs rm -rf >"$E2" 2>&1 || Fail "rm"


#======   Delete old logs   ====================================

find "$logdir/" -type f -mtime "+90" -delete || Fail "rm-old-logs"
find "$logdir/" -type f -empty       -delete || Fail "rm-empty-logs"

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