diff --git a/README.md b/README.md
index f946f94..f35c721 100644
--- a/README.md
+++ b/README.md
@@ -17,7 +17,7 @@ ZFS replication script by Thorsten Spille <thorsten@spille-edv.de>
 
 #### Download and make executable
 ~~~
-wget -q --no-cache -O /usr/bin/bashclub-zsync https://git.bashclub.org/bashclub/zsync/raw/branch/main/bashclub-zsync/usr/bin/bashclub-zsync
+wget -q --no-cache -O /usr/bin/bashclub-zsync https://git.bashclub.org/bashclub/zsync/raw/branch/dev/bashclub-zsync/usr/bin/bashclub-zsync
 chmod +x /usr/bin/bashclub-zsync
 bashclub-zsync
 ~~~
diff --git a/bashclub-zsync/usr/bin/bashclub-zsync b/bashclub-zsync/usr/bin/bashclub-zsync
index 656dc5b..f7f3ab7 100644
--- a/bashclub-zsync/usr/bin/bashclub-zsync
+++ b/bashclub-zsync/usr/bin/bashclub-zsync
@@ -16,6 +16,7 @@ wc=$(which wc)
 tr=$(which tr)
 sed=$(which sed)
 zfs_auto_snapshot=$(which zfs-auto-snapshot)
+rc=0
 debug=
 
 #### default config file, can be changed with parameter -c
@@ -40,7 +41,7 @@ snapshot_filter="hourly|daily|weekly|monthly"
 # minimum count of snapshots per filter to keep
 min_keep=3
 
-# number of zfs snapshots to keep on source (0 = snapshot function disabled)
+# number of zfs snapshots to keep on source (0 or 1 = snapshot function disabled)
 zfs_auto_snapshot_keep=0
 
 # make snapshot via zfs-auto-snapshot before replication
@@ -76,7 +77,7 @@ function log() {
 
 # load config file
 if [ -f $conf ]; then
-    log "Reading configuration $conf"
+    log "[INFO] Reading configuration $conf"
     source $conf
 else
     mkdir -p $(dirname $conf)
@@ -90,18 +91,18 @@ min_keep=$min_keep
 zfs_auto_snapshot_keep=$zfs_auto_snapshot_keep
 zfs_auto_snapshot_label=$zfs_auto_snapshot_label
 EOF
-    log "Initial config file created. Please adjust and restart script. Exiting..."
+    log "[INFO] Initial config file created. Please adjust and restart script. Exiting..."
     usage 0
 fi
 
 if [[ $source == "" ]]; then
-    log "source is empty, switching to local mode."
+    log "[INFO] source is empty, switching to local mode."
     ssh=
     sshport=
-    log "Configuration:\n\ttarget=$target\n\ttag=$tag\n\tsnapshot_filter=$snapshot_filter\n\tmin_keep=$min_keep\n"
+    log "[INFO] Configuration:\n\ttarget=$target\n\ttag=$tag\n\tsnapshot_filter=$snapshot_filter\n\tmin_keep=$min_keep\nzfs_auto_snapshot_keep=$zfs_auto_snapshot_keep\nzfs_auto_snapshot_label=$zfs_auto_snapshot_label\n"
 else
     sshport=-p$sshport
-    log "Configuration:\n\ttarget=$target\n\tsource=$source\n\tsshport=$sshport\n\ttag=$tag\n\tsnapshot_filter=$snapshot_filter\n\tmin_keep=$min_keep\n"
+    log "[INFO] Configuration:\n\ttarget=$target\n\tsource=$source\n\tsshport=$sshport\n\ttag=$tag\n\tsnapshot_filter=$snapshot_filter\n\tmin_keep=$min_keep\nzfs_auto_snapshot_keep=$zfs_auto_snapshot_keep\nzfs_auto_snapshot_label=$zfs_auto_snapshot_label\n"
 fi
 
 local_os_id=$($grep -E "^ID=" /etc/os-release | $cut -d'=' -f2)
@@ -127,8 +128,8 @@ else
     sshcipher=-cchacha20-poly1305@openssh.com
 fi
 
-include_list="Included datasets:\n"
-exclude_list="Excluded datasets:\n"
+include_list="[INFO] Included datasets:\n"
+exclude_list="[INFO] Excluded datasets:\n"
 IFS=$'\n'
 for zvol in $($ssh $sshcipher $sshport $source "zfs get -H -o name,value,source -t filesystem,volume $tag"); do
     name=$(echo $zvol | $cut -f1)
@@ -155,7 +156,7 @@ else
     fi
 fi
 
-if [ $zfs_auto_snapshot_keep -gt 0 ]; then
+if [ $zfs_auto_snapshot_keep -gt 1 ]; then
     log "[DEBUG] Running zfs-auto-snapshot"
     $ssh $sshcipher $sshport $source "which zfs-auto-snapshot > /dev/null || exit 0 ; zfs-auto-snapshot --quiet --syslog --label=$zfs_auto_snapshot_label --keep=$zfs_auto_snapshot_keep //"
     if [[ $snapshot_filter == "" ]]; then
@@ -166,8 +167,9 @@ if [ $zfs_auto_snapshot_keep -gt 0 ]; then
 fi
 
 for name in "${syncvols[@]}"; do
-    log "Replicate $name"
-    if [[ $($ssh $sshcipher $sshport $source zfs get -H -o value type $name) == "filesystem" ]]; then
+    log "[INFO] Replicate $name"
+    fstype=$($ssh $sshcipher $sshport $source zfs get -H -o value type $name)
+    if [[ $fstype == "filesystem" ]]; then
         mp=-xmountpoint
         cm=-ocanmount=noauto
     else
@@ -175,7 +177,7 @@ for name in "${syncvols[@]}"; do
         cm=
     fi
 
-    if [[ $($ssh $sshcipher $sshport $source "zfs list -H -t snapshot -o name -S creation $name 2>/dev/null | grep -E \"$snapshot_filter\" | wc -l | tr -d ' '") -gt 0 ]]; then
+    if [[ $($ssh $sshcipher $sshport $source "zfs list -H -t snapshot -o name -S creation $name 2>/dev/null | grep -E \"@.*($snapshot_filter)\" | wc -l | tr -d ' '") -gt 0 ]]; then
         IFS=$' '
         if ! $zfs list -H $target/$name > /dev/null 2>&1 ; then
             if [[ $debug == "-v" ]]; then log "[DEBUG] $target/$name does not exist"; fi
@@ -183,7 +185,7 @@ for name in "${syncvols[@]}"; do
             for part in $(echo $target/$(echo $name | $cut -d'/' -f1) | $sed "s/\// /g"); do
                 if [ $($zfs list $prefix$part > /dev/null 2>&1 ; echo $?) -gt 0 ]; then
                     if [[ $debug == "-v" ]]; then log "[DEBUG] $prefix$part does not exist"; fi
-                    log "Creating $prefix$part"
+                    log "[INFO] Creating $prefix$part"
                     $zfs create -o canmount=noauto $autosnap -p $prefix$part
                 fi
                 prefix="$prefix$part/"
@@ -191,38 +193,50 @@ for name in "${syncvols[@]}"; do
 
             if [[ $debug == "-v" ]]; then log "[DEBUG] $name - Start initial replication"; fi
             IFS=$'\n'
-            for snap in $($ssh $sshcipher $sshport $source "zfs list -H -t snapshot -o name -S creation $name | grep -E \"$snapshot_filter\" | tail -1"); do
-                log "Start initial replication: $snap => $target/$(echo $name | $cut -d'/' -f1)"
+            for snap in $($ssh $sshcipher $sshport $source "zfs list -H -t snapshot -o name -S creation $name | grep -E \"@.*($snapshot_filter)\" | tail -1"); do
+                log "[INFO] Start initial replication: $snap => $target/$(echo $name | $cut -d'/' -f1)"
                 $ssh $sshcipher $sshport $source "zfs send -w -p $debug $snap" | $zfs receive $mp $cm -x $tag -x com.sun:auto-snapshot $debug -dF $target/$(echo $name | $cut -d'/' -f1)
+                if [ $? -gt $rc ]; then rc=1; log "[ERROR] initial replication to $target/$name failed."; fi
             done
         fi
 
         if [[ $debug == "-v" ]]; then log "[DEBUG] $name - Start incremental replication"; fi
         guid=$($zfs list -H -o guid -s creation -t snapshot $target/$name | $tail -1)
-        last=$($ssh $sshcipher $sshport $source "zfs list -H -o name,guid -t snapshot $name | grep $guid | tail -1 | cut -f1")
-        IFS=$'\n'
-        if [[ $($zfs get -H -o value canmount $target/$name) != "noauto" ]]; then
-            $zfs set canmount=noauto $target/$name
+        if [[ $guid != "" ]]; then
+            last=$($ssh $sshcipher $sshport $source "zfs list -H -o name,guid -t snapshot $name | grep $guid | tail -1 | cut -f1")
+            if [[ $last != "" ]]; then
+                IFS=$'\n'
+                if [[ $fstype == "filesystem" ]] && [[ $($zfs get -H -o value canmount $target/$name) != "noauto" ]]; then
+                    $zfs set canmount=noauto $target/$name
+                fi
+                for snap in $($ssh $sshcipher $sshport $source "zfs list -H -o name,guid -s creation -t snapshot $name | grep -E \"@.*($snapshot_filter)\" | grep --after-context=200 $guid | grep -v $guid | cut -f1"); do
+                    log "[INFO] Replicating delta of $last => $snap to $target/$name"
+                    $ssh $sshcipher $sshport $source "zfs send -w $debug -i $last $snap" | zfs receive -x $tag -x com.sun:auto-snapshot -F $debug $target/$name
+                    if [ $? -gt $rc ]; then rc=1; log "[ERROR] incremental replication to $target/$name failed."; fi
+                    last=$snap
+                done
+            else
+                log "[ERROR] No matching snapshot (guid: $guid) found on source filesystem. This can be outdated snapshots on target or a previously deleted and new created dataset $name on the source filesystem."
+                if [ $rc -eq 0 ]; then rc=1; fi
+            fi
+        else
+            log "[ERROR] No snapshot found on $target/$name to add incremental snapshots to. The target dataset (with all children) needs to be deleted and recreated via replication."
+            if [ $rc -eq 0 ]; then rc=1; fi
         fi
-        for snap in $($ssh $sshcipher $sshport $source "zfs list -H -o name,guid -s creation -t snapshot $name | grep -E \"$snapshot_filter\" | grep --after-context=200 $guid | grep -v $guid | cut -f1"); do
-            log "Replicating delta of $last => $snap to $target/$name"
-            $ssh $sshcipher $sshport $source "zfs send -w $debug -i $last $snap" | zfs receive -x $tag -x com.sun:auto-snapshot -F $debug $target/$name
-            last=$snap
-        done
 
         if [[ $debug == "-v" ]]; then log "[DEBUG] $name - Start deletion of old snapshots"; fi
         filter=$(echo -e $snapshot_filter | sed "s/|/\n/g")
         IFS=$'\n'
         for interval in $filter ; do
             if [[ $debug == "-v" ]]; then log "[DEBUG] $name - Checking interval $interval"; fi
-            guid=$($ssh $sshcipher $sshport $source "zfs list -H -o guid,name -S creation -t snapshot $name | grep -E \"(.*)@(.*)$interval\" | cut -f1 | tail -1")
+            guid=$($ssh $sshcipher $sshport $source "zfs list -H -o guid,name -S creation -t snapshot $name | grep -E \"@.*$interval\" | cut -f1 | tail -1")
             if [[ "$(echo -e "$guid" | sed 's/\n//g')" != "" ]]; then
-                snaps_to_delete=$($zfs list -H -o name,guid -S creation -t snapshot $target/$name | $grep -E "(.*)@(.*)$interval" | $grep --after-context=200 $guid | $grep -v $guid | $cut -f1)
-                snap_count=$($zfs list -H -o name,guid -S creation -t snapshot $target/$name | $grep -E "(.*)@(.*)$interval" | $wc -l | $tr -d ' ')
+                snaps_to_delete=$($zfs list -H -o name,guid -S creation -t snapshot $target/$name | $grep -E "@.*$interval" | $grep --after-context=200 $guid | $grep -v $guid | $cut -f1)
+                snap_count=$($zfs list -H -o name,guid -S creation -t snapshot $target/$name | $grep -E "@.*$interval" | $wc -l | $tr -d ' ')
 
                 for snap in $snaps_to_delete; do
                     if [[ $snap_count -gt $min_keep ]]; then
-                        log "Deleting $snap"
+                        log "[INFO] Deleting $snap"
                         if [[ $debug == "-v" ]]; then log "[DEBUG] $name - snap_count=$snap_count, min_keep=$min_keep"; fi
                         $zfs destroy $debug $snap
                         snap_count=$(expr $snap_count - 1)
@@ -236,3 +250,4 @@ for name in "${syncvols[@]}"; do
         if [[ $debug == "-v" ]]; then log "[DEBUG] $name - No snapshots found with filter $snapshot_filter"; fi
     fi
 done
+exit $rc
\ No newline at end of file