Merge pull request #99 from stuehmer/patch-2

Merge changes fom master and add workaround for DASH shell problems

.gitignore

@@ -1,2 +0,0 @@
-
-.DS_Store

Makefile

@@ -11,5 +11,7 @@ install:
 	install etc/zfs-auto-snapshot.cron.daily    $(DESTDIR)$(PREFIX)/etc/cron.daily/zfs-auto-snapshot
 	install etc/zfs-auto-snapshot.cron.weekly   $(DESTDIR)$(PREFIX)/etc/cron.weekly/zfs-auto-snapshot
 	install etc/zfs-auto-snapshot.cron.monthly  $(DESTDIR)$(PREFIX)/etc/cron.monthly/zfs-auto-snapshot
+	install -d $(DESTDIR)$(PREFIX)/share/man/man8
+	install src/zfs-auto-snapshot.8 $(DESTDIR)$(PREFIX)/share/man/man8/zfs-auto-snapshot.8
 	install -d $(DESTDIR)$(PREFIX)/sbin
 	install src/zfs-auto-snapshot.sh $(DESTDIR)$(PREFIX)/sbin/zfs-auto-snapshot

README

@@ -1,14 +1,12 @@
 zfs-auto-snapshot:
 
-An alternative implementation of the zfs-auto-snapshot service for Macosx 
-that is compatible with ZEVO community zfs.
+An alternative implementation of the zfs-auto-snapshot service for Linux
+that is compatible with zfs-linux and zfs-fuse.
 
 Automatically create, rotate, and destroy periodic ZFS snapshots. This is
 the utility that creates the @zfs-auto-snap_frequent, @zfs-auto-snap_hourly,
 @zfs-auto-snap_daily, @zfs-auto-snap_weekly, and @zfs-auto-snap_monthly
 snapshots if it is installed.
 
-It can backup to remote systems utilizing zfs send command.
-
 This program is a posixly correct bourne shell script.  It depends only on
 the zfs utilities and cron, and can run in the dash shell.

src/zfs-auto-snapshot.8

@@ -0,0 +1,70 @@
+.TH ZFS-AUTO-SNAPSHOT "8" "June 16, 2013" "zfs-auto-snapshot.sh" "System Administration Commands"
+.SH NAME
+zfs-auto-snapshot \- take regular ZFS snapshots
+.SH SYNOPSIS
+.B zfs-auto-snapshot
+[\fIoptions\fR] [\fI-l label\fR] \fI<'//' | name \fR[\fIname\fR...]\fI>\fR
+.SH DESCRIPTION
+.B zfs-auto-snapshot
+automatically creates, rotates, and destroys snapshots for all your
+ZFS datasets, and is compatible with both zfsonlinux and zfs-fuse.
+.SH OPTIONS
+.TP
+\fB\-\-default\-exclude\fR
+By default \fBzfs-auto-snapshot\fR will snapshot all datasets except
+for those in which the user-property \fBcom.sun:auto-snapshot\fR is
+set to \fBfalse\fR.  This option reverses the behavior and requires
+\fBcom.sun:auto-snapshot\fR to be set to \fBtrue\fR.
+.TP
+\fB\-d\fR, \fB\-\-debug\fR
+Print debugging messages.
+.TP
+\fB\-e\fR, \fB\-\-event\fR=\fIEVENT\fR
+Set the com.sun:auto\-snapshot\-desc property to EVENT.
+.TP
+\fB\-\-fast\fR
+Use a faster zfs list invocation.
+.TP
+\fB\-n\fR, \fB\-\-dry\-run\fR
+Print actions without actually doing anything.
+.TP
+\fB\-s\fR, \fB\-\-skip\-scrub\fR
+Do not snapshot filesystems in scrubbing pools.
+.TP
+\fB\-h\fR, \fB\-\-help\fR
+Print the usage message.
+.TP
+\fB\-k\fR, \fB\-\-keep\fR=\fINUM\fR
+Keep NUM recent snapshots and destroy older snapshots.
+.TP
+\fB\-l\fR, \fB\-\-label\fR=\fILAB\fR
+LAB is usually 'hourly', 'daily', or 'monthly'.
+.TP
+\fB\-p\fR, \fB\-\-prefix\fR=\fIPRE\fR
+PRE is 'zfs\-auto\-snap' by default.
+.TP
+\fB\-q\fR, \fB\-\-quiet\fR
+Suppress warnings and notices at the console.
+.TP
+\fB\-\-send\-full\fR=\fIF\fR
+Send zfs full backup. Unimplemented.
+.TP
+\fB\-\-send\-incr\fR=\fIF\fR
+Send zfs incremental backup. Unimplemented.
+.TP
+\fB\-\-sep\fR=\fICHAR\fR
+Use CHAR to separate date stamps in snapshot names.
+.TP
+\fB\-g\fR, \fB\-\-syslog\fR
+Write messages into the system log.
+.TP
+\fB\-r\fR, \fB\-\-recursive\fR
+Snapshot named filesystem and all descendants.
+.TP
+\fB\-v\fR, \fB\-\-verbose\fR
+Print info messages.
+.TP
+name
+Filesystem and volume names, or '//' for all ZFS datasets.
+.SH SEE ALSO
+.BR zfs (8)

src/zfs-auto-snapshot.sh

@@ -1,9 +1,8 @@
 #!/bin/bash
 
-# zfs-auto-snapshot for Linux and Macosx
+# zfs-auto-snapshot for Linux
 # Automatically create, rotate, and destroy periodic ZFS snapshots.
 # Copyright 2011 Darik Horn <dajhorn@vanadac.com>
-# zfs send options and macosx relevant changes by Matus Kral <matuskral@me.com>
 #
 # This program is free software; you can redistribute it and/or modify it under
 # the terms of the GNU General Public License as published by the Free Software
@@ -30,8 +29,9 @@ opt_backup_incremental=''
 opt_default_exclude=''
 opt_dry_run=''
 opt_event='-'
+opt_fast_zfs_list=''
 opt_keep=''
-opt_label='regular'
+opt_label=''
 opt_prefix='zfs-auto-snap'
 opt_recursive=''
 opt_sep='_'
@@ -39,75 +39,40 @@ opt_setauto=''
 opt_syslog=''
 opt_skip_scrub=''
 opt_verbose=''
-opt_remove=''
-opt_fallback='0'
-opt_force=''
-opt_sendprefix=''
-opt_send='no'
-opt_atonce='-I'
-opt_create='0'
-opt_destroy='0'
-
-# if pipe needs to be used, uncomment opt_pipe="|"
-opt_sendtocmd='ssh -1 root@media -i /var/root/.ssh/media.rsa1'
-opt_pipe='|'
+opt_pre_snapshot=''
+opt_post_snapshot=''
+opt_do_snapshots=1
 
 # Global summary statistics.
 DESTRUCTION_COUNT='0'
 SNAPSHOT_COUNT='0'
 WARNING_COUNT='0'
-CREATION_COUNT='0'
-SENT_COUNT='0'
-KEEP=''
-
-PLATFORM_LOC=''
-PLATFORM_REM=''
 
 # Other global variables.
-declare -a SNAPSHOTS_OLD_LOC=('')
-declare -a SNAPSHOTS_OLD_REM=('')
-declare -a CREATED_TARGETS=('')
-declare -a ZFS_REMOTE_LIST=('')
-declare -a ZFS_LOCAL_LIST=('')
-declare -a TARGETS_DRECURSIVE=('')
-declare -a TARGETS_DREGULAR=('')
-declare -a MOUNTED_LIST_LOC=('')
-declare -a MOUNTED_LIST_REM=('')
-declare -i RC=99
+SNAPSHOTS_OLD=''
 
-tmp_file_prefix="/tmp/zfs-auto-snapshot.XXXXXXXX"
-set -o pipefail
 
 print_usage ()
 {
 	echo "Usage: $0 [options] [-l label] <'//' | name [name...]>
   --default-exclude  Exclude datasets if com.sun:auto-snapshot is unset.
-  --remove-local=n   Remove local snapshots after successfully sent via --send-incr or --send-full but still keeps n newest snapshots
-                     (this will destroy snapshots named according to --prefix, but regardless of --label).
   -d, --debug        Print debugging messages.
   -e, --event=EVENT  Set the com.sun:auto-snapshot-desc property to EVENT.
+      --fast         Use a faster zfs list invocation.
   -n, --dry-run      Print actions without actually doing anything.
   -s, --skip-scrub   Do not snapshot filesystems in scrubbing pools.
   -h, --help         Print this usage message.
   -k, --keep=NUM     Keep NUM recent snapshots and destroy older snapshots.
-  -l, --label=LAB    LAB is usually 'hourly', 'daily', or 'monthly' (default is 'regular').
+  -l, --label=LAB    LAB is usually 'hourly', 'daily', or 'monthly'.
   -p, --prefix=PRE   PRE is 'zfs-auto-snap' by default.
   -q, --quiet        Suppress warnings and notices at the console.
-  -c, --create       Create missing filesystems at destination.
-  -i, --send-at-once Send more incremental snapshots at once in one package (-i argument is passed to zfs send instead of -I). 
-      --send-full=F  Send zfs full backup. F is target filesystem.
-      --send-incr=F  Send zfs incremental backup. F is target filesystem.
+      --send-full=F  Send zfs full backup. Unimplemented.
+      --send-incr=F  Send zfs incremental backup. Unimplemented.
       --sep=CHAR     Use CHAR to separate date stamps in snapshot names.
-  -X, --destroy      Destroy remote snapshots to allow --send-full if destination has snapshots (needed for -F in case incremental
-                     snapshots on local and remote do not match).
-  -F, --fallback     Allow fallback from --send-incr to --send-full, if incremental sending is not possible (filesystem on remote just
-                     created or snapshots do not match - see -X).  
   -g, --syslog       Write messages into the system log.
   -r, --recursive    Snapshot named filesystem and all descendants.
-  -R, --replication  Use zfs's replication (zfs send -R) instead of simple send over newly created snapshots (check man zfs for details).
-                     -f is used automatically. 
   -v, --verbose      Print info messages.
-  -f, --force        Passes -F argument to zfs receive (e.g. makes possible to overwrite remote filesystem during --send-full)
+      --destroy-only Only destroy older snapshots, do not create new ones.
       name           Filesystem and volume names, or '//' for all ZFS datasets.
 " 
 }
@@ -138,7 +103,6 @@ print_log () # level, message, ...
 		(war*)
 			test -n "$opt_syslog" && logger -t "$opt_prefix" -p daemon.warning $*
 			test -z "$opt_quiet" && echo Warning: $* 1>&2
-			WARNING_COUNT=$(( $WARNING_COUNT + 1 ))
 			;;
 		(not*)
 			test -n "$opt_syslog" && logger -t "$opt_prefix" -p daemon.notice $*
@@ -146,7 +110,7 @@ print_log () # level, message, ...
 			;;
 		(inf*)
 			# test -n "$opt_syslog" && logger -t "$opt_prefix" -p daemon.info $*
-			test -n "$opt_verbose" && echo $*
+			test -z ${opt_quiet+x} && test -n "$opt_verbose" && echo $*
 			;;
 		(deb*)
 			# test -n "$opt_syslog" && logger -t "$opt_prefix" -p daemon.debug $*
@@ -162,15 +126,13 @@ print_log () # level, message, ...
 
 do_run () # [argv]
 {
-
 	if [ -n "$opt_dry_run" ]
 	then
-		print_log notice "... running: $*"
+		echo $*
 		RC="$?"
 	else
 		eval $*
 		RC="$?"
-
 		if [ "$RC" -eq '0' ]
 		then
 			print_log debug "$*"
@@ -178,345 +140,84 @@ do_run () # [argv]
 			print_log warning "$* returned $RC"
 		fi
 	fi
-	
 	return "$RC"
 }
 
 
-do_unmount ()
-{
-	local TYPE="$1"
-	local FLAGS="$3"
-	local FSNAME="$4"
-	local SNAPNAME="$5"
-	local rsort_cmd='0'
-	local remote_cmd=''
-
-	case "$TYPE" in
-		(remote)
-            umount_list=( "${MOUNTED_LIST_REM[@]}" ) 
-			remote_cmd="$opt_sendtocmd"
-			;;
-		(local)
-            umount_list=( "${MOUNTED_LIST_LOC[@]}" )
-			;;
-	esac
-
-    if [ -n "$SNAPNAME" ]; then
-        SNAPNAME="@$SNAPNAME"
-    else
-		rsort_cmd='1'
-    fi
-    umount_list=( $(printf "%s\t%s\n" "${umount_list[@]}" | grep ^"$FSNAME$SNAPNAME" ) )
-
-    test -z "$umount_list" && return 0
-
-	# reverse sort the list if unmounting filesystem and not only snapshot
-    umount_list=($(printf "%s\t%s\n" "${umount_list[@]}" | awk -F'\t' '{print $2}'))
-    test $rsort_cmd -eq '1' && umount_list=($(printf "%s\n" "${umount_list[@]}"))
-
-	for kk in ${umount_list[@]}; do
-		print_log debug "Trying to unmount '$kk'."
-		umount_cmd="umount '$kk'"
-		if ! do_run "$remote_cmd" "$umount_cmd"; then return "$RC"; fi
-		test "$FLAGS" != "-r" && break
-	done
-
-	return 0
-}
-
-do_delete ()
-{
-
-    local DEL_TYPE="$1"
-    local FSSNAPNAME="$2"
-    local FLAGS="$3"
-    local FSNAME=$(echo $FSSNAPNAME | awk -F'@' '{print $1}')
-    local SNAPNAME=$(echo $FSSNAPNAME | awk -F'@' '{print $2}')
-    local remote_cmd=''
-
-    if [ "$FSSNAPNAME" = "$FSNAME" -a "$FLAGS" = "-r" ]; then
-        if [ "$opt_destroy" -ne '1' ]; then
-            print_log warning "Filesystem $FSNAME destroy requested, but option -X not specified. Aborting."
-            return 1
-        else
-            KEEP='0'
-        fi
-    fi
-
-    KEEP=$(( $KEEP - 1 ))
-    if [ "$KEEP" -le '0' ]
-    then
-        if do_unmount "$DEL_TYPE" "" "$FLAGS" "$FSNAME" "$SNAPNAME"; then
-            if [ "$DEL_TYPE" = "remote" ]; then
-                remote_cmd="$opt_sendtocmd"
-            fi
-            if do_run "$remote_cmd" "zfs destroy $FLAGS '$FSSNAPNAME'"; then
-                DESTRUCTION_COUNT=$(( $DESTRUCTION_COUNT + 1 ))
-            fi
-        fi
-    fi
-
-    return "$RC"
-}
-
-is_member ()
-{
-    local ARRAY=(${1})
-    local MEMBER="$2"
-    declare -i ISMEMBER=0
-    
-    result=$(printf "%s\n" "${ARRAY[@]}"| grep -m1 -x "$MEMBER")
-    if [ -n "$result" -a -z "${result#$MEMBER}" ]; then ISMEMBER=1; fi
-    
-    return "$ISMEMBER"
-}
-
-do_send ()
-{
-    local SENDTYPE="$1"
-    local SNAPFROM="$2"
-    local SNAPTO="$3"
-    local SENDFLAGS="$4"
-    local REMOTEFS="$5"
-    local list_child=('')
-
-    if [ "$SENDFLAGS" = "-R" -a "$SENDTYPE" = "full" ]; then
-        # for full send with -R, target filesystem must be with no snapshots (including snapshots on child filesystems)
-        list_child=( $(printf "%s\n" "${SNAPSHOTS_OLD_REM[@]}" | grep ^"$REMOTEFS/" ) )
-    fi
-    if [ "$SENDTYPE" = "full" ]; then
-        list_child=( ${list_child[@]} $(printf "%s\n" "${SNAPSHOTS_OLD_REM[@]}" | grep ^"$REMOTEFS@" ) )
-    fi
-
-    for ll in ${list_child[@]}; do
-        if do_delete "remote" "$ll" ""; then
-            continue
-        fi
-        print_log debug "Can't destroy remote filesystem $REMOTEFS ($ll). Can't continue with send-full."
-        return 1
-    done
-
-    test $SENDTYPE = "incr" && do_run "zfs send " "$SENDFLAGS" "$opt_atonce  $SNAPFROM   $SNAPTO" "$opt_pipe" "$opt_sendtocmd" "zfs recv  $opt_force -u $REMOTEFS"
-    test $SENDTYPE = "full" && do_run "zfs send " "$SENDFLAGS" "$SNAPTO" "$opt_pipe" "$opt_sendtocmd" "zfs recv $opt_force -u $REMOTEFS"
-
-    return "$RC"
-}
-
 do_snapshots () # properties, flags, snapname, oldglob, [targets...]
 {
 	local PROPS="$1"
-	local sFLAGS="$2"
+	local FLAGS="$2"
 	local NAME="$3"
 	local GLOB="$4"
-	local TARGETS=(${5})
+	local TARGETS="$5"
 	local KEEP=''
-	local LAST_REMOTE=''
+	local LABEL="$6"
+	local RUNSNAP=1
 
-    if test "$sFLAGS" = '-R'; then
-        FLAGS='-r'
-        SNexp='.*'
-    else
-        FLAGS=''
-    fi
+	# global DESTRUCTION_COUNT
+	# global SNAPSHOT_COUNT
+	# global WARNING_COUNT
+	# global SNAPSHOTS_OLD
 
-	for ii in ${TARGETS[@]}
+	for ii in $TARGETS
 	do
-
-		FALLBACK='0'
-		SND_RC='1'
-
-		print_log debug "--> Snapshooting $ii"
-
-		if ! do_run "zfs snapshot $PROPS $FLAGS '$ii@$NAME'" 
+		if [ -n "$opt_do_snapshots" ]
 		then
-			continue
-		fi
-		SNAPSHOT_COUNT=$(( $SNAPSHOT_COUNT + 1 ))
-
-		if [ "$opt_send" = "incr" ]
-		then
-
-            LAST_REMOTE=$(printf "%s\n" ${SNAPSHOTS_OLD_REM[@]} | grep ^$opt_sendprefix/$ii@ | grep -m1 . | awk -F'@' '{print $2}')
-
-            # in case of -R and incremental send, receiving side needs to have $LAST_REMOTE snapshot for each replicated filesystem
-            if [ "$FLAGS" = "-r" ]; then
-                snaps_needed=$(( $(printf "%s\n" ${ZFS_LIST_LOC[@]} | grep ^"$ii/") + 1 )) 
-            else
-                snaps_needed='1'
-            fi
-
-            # remote filesystem just created. if -R run
-			if ! is_member "${CREATED_TARGETS[*]}" "$opt_sendprefix/$ii"
-            then  
-				FALLBACK='2'
-			elif [ -z "$LAST_REMOTE" ]
+			if [ "$opt_pre_snapshot" != "" ]
 			then
-				# no snapshot on remote
-				FALLBACK='1'
-			elif [ "$snaps_needed" -ne $(printf "%s\n" ${SNAPSHOTS_OLD_REM[@]} | grep -c -e ^"$opt_sendprefix/$ii$SNexp@$LAST_REMOTE" ) -o \
-                "$snaps_needed" -ne $(printf "%s\n" ${SNAPSHOTS_OLD_LOC[@]} | grep -c -e ^"$ii$SNexp@$LAST_REMOTE" ) ]
-			then
-				FALLBACK='3'
-            else
-				FALLBACK='0'
+				do_run "$opt_pre_snapshot $ii $NAME" || RUNSNAP=0
 			fi
-
-			case "$FALLBACK" in
-				(1)
-					print_log info "Going back to full send, no snapshot exists at destination: $ii"
-					;;
-				(2)
-					print_log info "Going back to full send, remote filesystem was just created: $ii"
-					;;
-				(3)
-					if [ "$FLAGS" = "-r" ]; then
-                        print_log info "Going back to full send, last snapshot on remote is not the last one for whole recursion: $opt_sendprefix/$ii@$LAST_REMOTE"
-                    else
-                        print_log info "Going back to full send, last snapshot on remote is not available on local: $opt_sendprefix/$ii@$LAST_REMOTE"
-                    fi
-                    ;;
-				(0)
-					do_send "incr" "$ii@$LAST_REMOTE" "$ii@$NAME" "$sFLAGS" "$opt_sendprefix/$ii" 
-					SND_RC="$?"
-					;;
-			esac
+			if [ $RUNSNAP -eq 1 ] && do_run "zfs snapshot $PROPS $FLAGS '$ii@$NAME'"
+			then
+				[ "$opt_post_snapshot" != "" ] && do_run "$opt_post_snapshot $ii $NAME"
+				SNAPSHOT_COUNT=$(( $SNAPSHOT_COUNT + 1 ))
+			else
+				WARNING_COUNT=$(( $WARNING_COUNT + 1 ))
+				continue
+			fi 
 		fi
 
-		if [ "$opt_send" = "full" -o "$FALLBACK" -ne '0' -a "$opt_fallback" -eq '1' ]; then
-			do_send "full" "" "$ii@$NAME" "$sFLAGS" "$opt_sendprefix/$ii"
-			SND_RC="$?"
-		fi
-		test "$SND_RC" -eq '0' && SENT_COUNT=$(( $SENT_COUNT + 1 ))
-
 		# Retain at most $opt_keep number of old snapshots of this filesystem,
 		# including the one that was just recently created.
-		if [ -z "$opt_keep" ]
-		then
-			print_log debug "Number of snapshots not specified. Keeping all."
-			continue
-		elif [ "$opt_send" != "no" ] && [ "$SND_RC" -ne '0' ]
-		then
-			print_log debug "Sending of filesystem was requested, but send failed. Ommiting destroy procedures."
-			continue
-		elif [ "$opt_send" != "no" -a -n "$opt_remove" ]
-		then
-			KEEP="$opt_remove"
-		else
-			KEEP="$opt_keep"
-		fi
-		print_log debug "Destroying local snapshots, keeping $KEEP."		    
-
+		test -z "$opt_keep" && continue
+		KEEP="$opt_keep"
+		
 		# ASSERT: The old snapshot list is sorted by increasing age.
-		for jj in ${SNAPSHOTS_OLD_LOC[@]}
+		# Match on both $GLOB *and* label.
+		while IFS='	' read -ra arrjj
 		do
 			# Check whether this is an old snapshot of the filesystem.
-			test -z "${jj#$ii@$GLOB}" -o -z "${jj##$ii@$opt_prefix*}" -a -n "$opt_remove" \
-				-a "$opt_send" != "no" && do_delete "local" "$jj" "$FLAGS"
-		done
-
-		if [ "$opt_send" = "no" ]
-		then
-			print_log debug "No sending option specified, skipping remote snapshot removal."
-			continue
-		elif [ "$sFLAGS" = "-R" ]
-		then
-			print_log debug "Replication specified, remote snapshots were removed while sending."
-			continue
-		elif [ "$opt_destroy" -eq '1' -a "$FALLBACK" -ne '0' -o "$opt_send" = "full" ]
-		then
-			print_log debug "Sent full copy, all remote snapshots were already destroyed."
-			continue
-		else
-			KEEP="$opt_keep"
-			print_log debug "Destroying remote snapshots, keeping only $KEEP."
-		fi
-
-		# ASSERT: The old snapshot list is sorted by increasing age.
-		for jj in ${SNAPSHOTS_OLD_REM[@]}
-		do
-			# Check whether this is an old snapshot of the filesystem.
-			test -z "${jj#$opt_sendprefix/$ii@$GLOB}" && do_delete "remote" "$jj" "$FLAGS" 
-		done
-
-	done
-}
-
-do_getmountedfs ()
-{
-
-    local MOUNTED_TYPE="$1"
-    local MOUNTED_LIST
-    local remote_cmd=''
-
-    case "$MOUNTED_TYPE" in
-        (remote)
-            remote_cmd="$opt_sendtocmd"
-            PLATFORM="$PLATFORM_REM"
-            ;;
-        (local)
-            remote_cmd=""
-            PLATFORM="$PLATFORM_LOC"
-            ;;
-    esac
-
-    case "$PLATFORM" in
-        (Linux)
-            MOUNTED_LIST=( $(eval $remote_cmd cat /proc/mounts | grep zfs | awk -F' ' '{OFS="\t"}{print $1,$2}' ) )
-            ;;
-        (Darwin)
-            MOUNTED_LIST=( $(eval $remote_cmd zfs mount | awk -F' ' '{OFS="\t"}{print $1,$2}') $(eval $remote_cmd mount -t zfs | grep @ | awk -F' ' '{OFS="\t"}{print $1,$3}') )
-            ;;
-    esac
-
-    printf "%s\t%s\n" "${MOUNTED_LIST[@]}" | sort  
-}
-
-do_createfs ()
-{
-
-	local FS=(${1})
-
-	for ii in ${FS[@]}; do
-
-		print_log debug "checking: $opt_sendprefix/$ii"
-
-		if is_member "${ZFS_REMOTE_LIST[*]}" "$opt_sendprefix/$ii" -eq 0
-		then
-			print_log debug "creating: $opt_sendprefix/$ii"
-
-			if do_run "$opt_sendtocmd" "zfs create $opt_sendprefix/$ii"
-			then 
-				CREATION_COUNT=$(( $CREATION_COUNT + 1 ))
-				CREATED_TARGETS=( ${CREATED_TARGETS[@]} "$opt_sendprefix/$ii" )
+			if [ -z "${arrjj[1]#$ii@$GLOB}" ]
+			then
+				# Check whether the snapshot has the same label property
+				test "${arrjj[0]}" = "$LABEL" || continue
+			
+				KEEP=$(( $KEEP - 1 ))
+				if [ "$KEEP" -le '0' ]
+				then
+					if do_run "zfs destroy -d $FLAGS '${arrjj[1]}'" 
+					then
+						DESTRUCTION_COUNT=$(( $DESTRUCTION_COUNT + 1 ))
+					else
+						WARNING_COUNT=$(( $WARNING_COUNT + 1 ))
+					fi
+				fi
 			fi
-		fi
+		done <<< "$SNAPSHOTS_OLD"
 	done
-
 }
 
+
 # main ()
 # {
-                    
-PLATFORM_LOC=`uname`
-case "$PLATFORM_LOC" in 
-    (Linux)
-        getopt_cmd='getopt'
-        ;;
-    (Darwin)
-        getopt_cmd='/opt/local/bin/getopt'
-        ;;
-    (*)
-        print_log error "Local system not known ($PLATFORM_LOC) - needs one of Darwin, Linux. Exiting."
-        exit 300
-        ;;
-esac
 
-GETOPT=$("$getopt_cmd" \
-  --longoptions=default-exclude,dry-run,skip-scrub,recursive,send-atonce \
-  --longoptions=event:,keep:,label:,prefix:,sep:,create,fallback,rollback \
-  --longoptions=debug,help,quiet,syslog,verbose,send-full:,send-incr:,remove-local:,destroy \
-  --options=dnshe:l:k:p:rs:qgvfixcXFRb \
+GETOPT=$(getopt \
+  --longoptions=default-exclude,dry-run,fast,skip-scrub,recursive \
+  --longoptions=event:,keep:,label:,prefix:,sep: \
+  --longoptions=debug,help,quiet,syslog,verbose \
+  --longoptions=pre-snapshot:,post-snapshot:,destroy-only \
+  --options=dnshe:l:k:p:rs:qgv \
   -- "$@" ) \
   || exit 128
 
@@ -531,11 +232,7 @@ do
 			opt_verbose='1'
 			shift 1
 			;;
-		(-c|--create)
-			opt_create='1'
-			shift 1
-			;;
-		(-x|--default-exclude)
+		(--default-exclude)
 			opt_default_exclude='1'
 			shift 1
 			;;
@@ -543,13 +240,17 @@ do
 			if [ "${#2}" -gt '1024' ]
 			then
 				print_log error "The $1 parameter must be less than 1025 characters."
-				exit 239
+				exit 139
 			elif [ "${#2}" -gt '0' ]
 			then
 				opt_event="$2"
 			fi
 			shift 2
 			;;
+		(--fast)
+			opt_fast_zfs_list='1'
+			shift 1
+			;;
 		(-n|--dry-run)
 			opt_dry_run='1'
 			shift 1
@@ -566,7 +267,7 @@ do
 			if ! test "$2" -gt '0' 2>/dev/null
 			then
 				print_log error "The $1 parameter must be a positive integer."
-				exit 229
+				exit 129
 			fi
 			opt_keep="$2"
 			shift 2
@@ -582,7 +283,7 @@ do
 				case $opt_prefix in
 					([![:alnum:]_.:\ -]*)
 						print_log error "The $1 parameter must be alphanumeric."
-						exit 230
+						exit 130
 						;;
 				esac
 				opt_prefix="${opt_prefix#?}"
@@ -592,25 +293,12 @@ do
 			;;
 		(-q|--quiet)
 			opt_debug=''
-			opt_quiet='1' 
+			opt_quiet='1'
 			opt_verbose=''
 			shift 1
 			;;
 		(-r|--recursive)
-			opt_recursive=' '
-			shift 1
-			;;
-		(-R|--replication)
-			opt_recursive='-R'
-			opt_force='-F'
-			shift 1
-			;;
-		(-X|--destroy)
-			opt_destroy='1'
-			shift 1
-			;;
-		(-F|--fallback)
-			opt_fallback='1'
+			opt_recursive='1'
 			shift 1
 			;;
 		(--sep)
@@ -620,67 +308,35 @@ do
 					;;
 				('')
 					print_log error "The $1 parameter must be non-empty."
-					exit 231
+					exit 131
 					;;
 				(*)
 					print_log error "The $1 parameter must be one alphanumeric character."
-					exit 232
+					exit 132
 					;;
 			esac
 			opt_sep="$2"
 			shift 2
 			;;
-		(--send-full)
-			if [ -n "$opt_sendprefix" ]; then
-				print_log error "Only one of --send-incr and --send-full must be specified."
-				exit 239
-			fi
-			if [ -z "$2" ]; then
-				print_log error "Target filesystem needs to be specified with --send-full."
-				exit 243
-			fi
-			opt_sendprefix="$2"
-			opt_send='full'			
-			shift 2
-			;;
-		(--send-incr)
-			opt_sendincr="$2"
-			if [ -n "$opt_sendprefix" ]; then
-				print_log error "Only one of --send-incr and --send-full must be specified."
-				exit 240
-			fi
-			if [ -z "$2" ]; then
-				print_log error "Target filesystem needs to be specified with --send-incr."
-				exit 242
-			fi
-			opt_sendprefix="$2"
-			opt_send='incr'			
-			shift 2
-			;;
 		(-g|--syslog)
 			opt_syslog='1'
 			shift 1
 			;;
-		(-i|--send-atonce)
-			opt_atonce='-i'
-			shift 1
-			;;			
-		(--remove-local)
-			if ! test "$2" -gt '0' 2>/dev/null
-			then
-				print_log error "The $1 parameter must be a positive integer."
-				exit 241
-			fi
-			opt_remove="$2"
-			shift 2
-			;;
 		(-v|--verbose)
 			opt_quiet=''
 			opt_verbose='1'
 			shift 1
 			;;
-		(-f|--force|-b|--rollback)
-			opt_force='-F'
+		(--pre-snapshot)
+			opt_pre_snapshot="$2"
+			shift 2
+			;;
+		(--post-snapshot)
+			opt_post_snapshot="$2"
+			shift 2
+			;;
+		(--destroy-only)
+			opt_do_snapshots=''
 			shift 1
 			;;
 		(--)
@@ -696,13 +352,6 @@ then
 	exit 133
 fi 
 
-if [ -f "${tmp_file_prefix%%X*}"* ]; then 
-    print_log error "another copy is running ..."
-    exit 99
-fi  
-LOCKFILE=$(mktemp $tmp_file_prefix)
-trap "rm -f '$LOCKFILE'; exit $?" INT TERM EXIT
-
 # Count the number of times '//' appears on the command line.
 SLASHIES='0'
 for ii in "$@"
@@ -723,11 +372,23 @@ fi
 ZPOOL_STATUS=$(env LC_ALL=C zpool status 2>&1 ) \
   || { print_log error "zpool status $?: $ZPOOL_STATUS"; exit 135; }
 
+
 ZFS_LIST=$(env LC_ALL=C zfs list -H -t filesystem,volume -s name \
-  -o name,com.sun:auto-snapshot,com.sun:auto-snapshot:"$opt_label",mountpoint,canmount,snapdir) \
+  -o name,com.sun:auto-snapshot,com.sun:auto-snapshot:"$opt_label") \
   || { print_log error "zfs list $?: $ZFS_LIST"; exit 136; }
-  
-ZFS_LOCAL_LIST=($(echo "$ZFS_LIST" | awk -F'\t' '{ORS="\n"}{print $1}'))
+
+if [ -n "$opt_fast_zfs_list" ]
+then
+ 	SNAPSHOTS_OLD=$(env LC_ALL=C zfs list -H -t snapshot -o com.sun:auto-snapshot-label,name -s name | \
+		grep $opt_prefix | \
+		awk '{ print substr( $0, length($0) - 14, length($0) ) " " $0}' | \
+		sort -r -k1,1 -k3,2 | \
+		awk '{ print substr( $0, 17, length($0) )}') \
+	  || { print_log error "zfs list $?: $SNAPSHOTS_OLD"; exit 137; }
+else
+        SNAPSHOTS_OLD=$(env LC_ALL=C zfs list -H -t snapshot -S creation -o com.sun:auto-snapshot-label,name) \
+	  || { print_log error "zfs list $?: $SNAPSHOTS_OLD"; exit 137; }
+fi
 
 # Verify that each argument is a filesystem or volume.
 for ii in "$@"
@@ -755,29 +416,28 @@ ZPOOLS_NOTREADY=$(echo "$ZPOOL_STATUS" | awk -F ': ' \
    $1 ~ /^ *state$/ && $2 !~ /ONLINE|DEGRADED/ { print pool } ' \
   | sort)
 
-# Get a list of datasets for which snapshots are not explicitly disabled.
-CANDIDATES=$(echo "$ZFS_LIST" | awk -F '\t' \
-  'tolower($2) !~ /false/ && tolower($3) !~ /false/ {print $1}' )
+# Get a list of datasets for which snapshots are explicitly disabled.
+NOAUTO=$(echo "$ZFS_LIST" | awk -F '\t' \
+  'tolower($2) ~ /false/ || tolower($3) ~ /false/ {print $1}')
 
 # If the --default-exclude flag is set, then exclude all datasets that lack
 # an explicit com.sun:auto-snapshot* property. Otherwise, include them.
 if [ -n "$opt_default_exclude" ]
 then
-	# Get a list of datasets for which snapshots are not explicitly enabled.
-	NOAUTO=$(echo "$ZFS_LIST" | awk -F '\t' \
-	  'tolower($2) !~ /true/ && tolower($3) !~ /true/ {print $1}')
+	# Get a list of datasets for which snapshots are explicitly enabled.
+	CANDIDATES=$(echo "$ZFS_LIST" | awk -F '\t' \
+	  'tolower($2) ~ /true/ || tolower($3) ~ /true/ {print $1}')
 else
-	# Get a list of datasets for which snapshots are explicitly disabled.
-	NOAUTO=$(echo "$ZFS_LIST" | awk -F '\t' \
-	  'tolower($2) ~ /false/ || tolower($3) ~ /false/ {print $1}')
+	# Invert the NOAUTO list.
+	CANDIDATES=$(echo "$ZFS_LIST" | awk -F '\t' \
+	  'tolower($2) !~ /false/ && tolower($3) !~ /false/ {print $1}')
 fi
 
 # Initialize the list of datasets that will get a recursive snapshot.
-declare -a TARGETS_DRECURSIVE=('')
-declare -a TARGETS_TMP_RECURSIVE=('')
+TARGETS_RECURSIVE=''
 
 # Initialize the list of datasets that will get a non-recursive snapshot.
-declare -a TARGETS_DREGULAR=('')
+TARGETS_REGULAR=''
 
 for ii in $CANDIDATES
 do
@@ -785,12 +445,13 @@ do
 	# Suppose ii=tanker/foo and jj=tank sometime during the loop.
 	# Just testing "$ii" != ${ii#$jj} would incorrectly match.
 	iii="$ii/"
-	
-	# Exclude datasets that are not named on the command line.
+
+
+    # Exclude datasets that are not named on the command line.
 	IN_ARGS='0'
 	for jj in "$@"
 	do
-		if [ "$jj" = '//' -o "$jj" = "$ii" -o -n "$opt_recursive" -a -z "${ii##$jj/*}" ]
+		if [ "$jj" = '//' -o "$jj" = "$ii" ]
 		then
 			IN_ARGS=$(( $IN_ARGS + 1 ))
 		fi
@@ -799,7 +460,7 @@ do
 	then
 		continue
 	fi
-	
+
 	# Exclude datasets in pools that cannot do a snapshot.
 	for jj in $ZPOOLS_NOTREADY
 	do
@@ -828,31 +489,29 @@ do
 		fi
 	done
 
-    noauto_parent='0'
-    for jj in $NOAUTO
+	for jj in $NOAUTO
 	do
 		# Ibid regarding iii.
 		jjj="$jj/"
-		
-	    if [ "$jjj" = "$iii" ]
-        then
+
+		# The --recursive switch only matters for non-wild arguments.
+		if [ -z "$opt_recursive" -a "$1" != '//' ]
+		then
+			# Snapshot this dataset non-recursively.
+			print_log debug "Including $ii for regular snapshot."
+			TARGETS_REGULAR="${TARGETS_REGULAR:+$TARGETS_REGULAR	}$ii" # nb: \t
 			continue 2
 		# Check whether the candidate name is a prefix of any excluded dataset name.
 		elif [ "$jjj" != "${jjj#$iii}" ]
 		then
-		    noauto_parent='1' && break
-        fi
+			# Snapshot this dataset non-recursively.
+			print_log debug "Including $ii for regular snapshot."
+			TARGETS_REGULAR="${TARGETS_REGULAR:+$TARGETS_REGULAR	}$ii" # nb: \t
+			continue 2
+		fi
 	done
 
-    # not scrubbing 
-    if [ -z "$opt_recursive" -a "$1" != '//' -o "$noauto_parent" = '1' ]
-    then
-        print_log debug "Including $ii for regular snapshot."
-        TARGETS_DREGULAR=( ${TARGETS_DREGULAR[@]} $( printf "%s\n" $ii))
-        continue
-    fi
-
-	for jj in ${TARGETS_TMP_RECURSIVE[@]}
+	for jj in $TARGETS_RECURSIVE
 	do
 		# Ibid regarding iii.
 		jjj="$jj/"
@@ -873,84 +532,55 @@ do
 	#   * Is not the descendant of an already included filesystem.
 	#
 	print_log debug "Including $ii for recursive snapshot."
-	TARGETS_TMP_RECURSIVE=( ${TARGETS_TMP_RECURSIVE[@]} $( printf "%s\n" $ii) )
-	
+	TARGETS_RECURSIVE="${TARGETS_RECURSIVE:+$TARGETS_RECURSIVE	}$ii" # nb: \t
 done
 
 # Linux lacks SMF and the notion of an FMRI event, but always set this property
 # because the SUNW program does. The dash character is the default.
-SNAPPROP="-o com.sun:auto-snapshot-desc='$opt_event'"
+SNAPPROP="-o com.sun:auto-snapshot-desc='$opt_event' -o com.sun:auto-snapshot-label=$opt_label"
 
 # ISO style date; fifteen characters: YYYY-MM-DD-HHMM
 # On Solaris %H%M expands to 12h34.
-DATE=$(date +%F-%H%M)
+DATE=$(date --utc +%F-%H%M)
 
 # The snapshot name after the @ symbol.
-SNAPNAME="$opt_prefix${opt_label:+$opt_sep$opt_label-$DATE}"
+SNAPNAME="$opt_prefix$opt_sep$DATE"
 
 # The expression for matching old snapshots.  -YYYY-MM-DD-HHMM
-SNAPGLOB="$opt_prefix${opt_label:+?$opt_label}????????????????"
+SNAPGLOB="${opt_prefix}????????????????"
 
-if test -n "$TARGETS_DREGULAR"; then
-    print_log info "Doing regular snapshots of ${TARGETS_DREGULAR[@]}"
-    SNAPSHOTS_OLD_LOC=( $(eval zfs list -r -d 1 -H -t snapshot -S creation -o name $(printf "%s " ${TARGETS_DREGULAR[@]}) ))
-fi
+if [ -n "$opt_do_snapshots" ]
+then
+	test -n "$TARGETS_REGULAR" \
+	  && print_log info "Doing regular snapshots of $TARGETS_REGULAR"
 
-if test -n "$TARGETS_TMP_RECURSIVE"; then
-    print_log info "Doing recursive snapshots of ${TARGETS_TMP_RECURSIVE[@]}"
-    SNAPSHOTS_OLD_LOC=( ${SNAPSHOTS_OLD_LOC[@]} $(eval zfs list -r -H -t snapshot -S creation -o name $(printf "%s " ${TARGETS_TMP_RECURSIVE[@]} ) )) \
-        || { print_log error "zfs list $?: $SNAPSHOTS_OLD_LOC"; exit 137; }
+	test -n "$TARGETS_RECURSIVE" \
+	  && print_log info "Doing recursive snapshots of $TARGETS_RECURSIVE"
+
+	if test -n "$opt_keep" && [ "$opt_keep" -ge "1" ]
+	then
+		print_log info "Destroying all but the newest $opt_keep snapshots of each dataset."
+	fi
+elif test -n "$opt_keep" && [ "$opt_keep" -ge "1" ]
+then
+	test -n "$TARGETS_REGULAR" \
+	  && print_log info "Destroying all but the newest $opt_keep snapshots of $TARGETS_REGULAR"
+
+	test -n "$TARGETS_RECURSIVE" \
+	  && print_log info "Recursively destroying all but the newest $opt_keep snapshots of $TARGETS_RECURSIVE"
+else
+	print_log notice "Only destroying snapshots, but count of snapshots to preserve not given. Nothing to do."
 fi
 
 test -n "$opt_dry_run" \
   && print_log info "Doing a dry run. Not running these commands..."
 
-# expand FS list if replication is not used 
-if [ "$opt_recursive" = ' ' -o "$1" = "//" ]
-then
-    for ii in ${TARGETS_TMP_RECURSIVE[@]}; do TARGETS_DRECURSIVE=( ${TARGETS_DRECURSIVE[@]} $(printf "$ii\n") $(printf "%s\n" ${ZFS_LOCAL_LIST[@]} | grep ^"$ii/") ); done
-else
-    TARGETS_DRECURSIVE=( ${TARGETS_TMP_RECURSIVE[@]} )
-fi
-
-MOUNTED_LIST_LOC=$(eval do_getmountedfs "local")
-
-# initialize remote system parameters, filesystems, mounts and snapshots
-if [ "$opt_send" != "no" ]
-then
-    PLATFORM_REM=$(eval "$opt_sendtocmd" "uname")
-
-    case "$PLATFORM_REM" in 
-        (Linux|Darwin)
-            ;;
-        (*)
-            print_log error "Remote system not known ($PLATFORM_REM) - needs one of Darwin, Linux. Exiting."
-            exit 301
-            ;;
-    esac
-
-    MOUNTED_LIST_REM=$(eval do_getmountedfs "remote")
-
-    SNAPSHOTS_OLD_REM=($(eval "$opt_sendtocmd" zfs list -r -H -t snapshot -S creation -o name "$opt_sendprefix")) \
-                          || { print_log error "zfs list $?: $SNAPSHOTS_OLD_REM"; exit 140; }
-
-    ZFS_REMOTE_LIST=($(eval "$opt_sendtocmd" zfs list -H -t filesystem,volume -s name -o name)) \
-                         || { print_log error "$opt_sendtocmd zfs list $?: $ZFS_REMOTE_LIST"; exit 139; }
-fi
-
-if [ "$opt_create" -eq '1' -a "$opt_send" != "no" ]; then
-    do_createfs "${TARGETS_DREGULAR[*]}"
-    do_createfs "${TARGETS_DRECURSIVE[*]}"
-fi
-
-do_snapshots "$SNAPPROP" "" "$SNAPNAME" "$SNAPGLOB" "${TARGETS_DREGULAR[*]}"
-do_snapshots "$SNAPPROP" "$opt_recursive" "$SNAPNAME" "$SNAPGLOB" "${TARGETS_DRECURSIVE[*]}"
+do_snapshots "$SNAPPROP" ""   "$SNAPNAME" "$SNAPGLOB" "$TARGETS_REGULAR" "$opt_label"
+do_snapshots "$SNAPPROP" "-r" "$SNAPNAME" "$SNAPGLOB" "$TARGETS_RECURSIVE" "$opt_label"
 
 print_log notice "@$SNAPNAME," \
-  "$SNAPSHOT_COUNT created snapshots," \
-  "$SENT_COUNT sent snapshots," \
+  "$SNAPSHOT_COUNT created," \
   "$DESTRUCTION_COUNT destroyed," \
-  "$CREATION_COUNT created filesystems," \
   "$WARNING_COUNT warnings."
 
 exit 0