From 8a2a673c58ddbc1b222ec65a75c4db77b9e8b4e4 Mon Sep 17 00:00:00 2001
From: Attie Grande <attie@attie.co.uk>
Date: Sat, 6 Jan 2018 11:01:44 +0000
Subject: [PATCH 01/14] fixed loud 'NEWEST SNAPSHOT' message

---
 syncoid | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/syncoid b/syncoid
index 7337f5b..d039d15 100755
--- a/syncoid
+++ b/syncoid
@@ -597,7 +597,7 @@ sub getnewestsnapshot {
 	my $snaps = shift;
 	foreach my $snap ( sort { $snaps{'source'}{$b}{'creation'}<=>$snaps{'source'}{$a}{'creation'} } keys %{ $snaps{'source'} }) {
 		# return on first snap found - it's the newest
-		print "NEWEST SNAPSHOT: $snap\n";
+		if (!$quiet) { print "NEWEST SNAPSHOT: $snap\n"; }
 		return $snap;
 	}
 	# must not have had any snapshots on source - looks like we'd better create one!

From e902df1ef2347aa08aeb20478a2b988695dd5d20 Mon Sep 17 00:00:00 2001
From: Attie Grande <attie@attie.co.uk>
Date: Sat, 6 Jan 2018 11:03:02 +0000
Subject: [PATCH 02/14] also made warnings quiet

---
 syncoid | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/syncoid b/syncoid
index d039d15..aec99cd 100755
--- a/syncoid
+++ b/syncoid
@@ -452,13 +452,13 @@ sub checkcommands {
 
 	if ($avail{'sourcecompress'} eq '') {
 		if ($compressargs{'rawcmd'} ne '') {
-			print "WARN: $compressargs{'rawcmd'} not available on source $s- sync will continue without compression.\n";
+			if (!$quiet) { print "WARN: $compressargs{'rawcmd'} not available on source $s- sync will continue without compression.\n"; }
 		}
 		$avail{'compress'} = 0;
 	}
 	if ($avail{'targetcompress'} eq '') {
 		if ($compressargs{'rawcmd'} ne '') {
-			print "WARN: $compressargs{'rawcmd'} not available on target $t - sync will continue without compression.\n";
+			if (!$quiet) { print "WARN: $compressargs{'rawcmd'} not available on target $t - sync will continue without compression.\n"; }
 		}
 		$avail{'compress'} = 0;
 	}
@@ -471,7 +471,7 @@ sub checkcommands {
 	# corner case - if source AND target are BOTH remote, we have to check for local compress too
 	if ($sourcehost ne '' && $targethost ne '' && $avail{'localcompress'} eq '') {
 		if ($compressargs{'rawcmd'} ne '') {
-			print "WARN: $compressargs{'rawcmd'} not available on local machine - sync will continue without compression.\n";
+			if (!$quiet) { print "WARN: $compressargs{'rawcmd'} not available on local machine - sync will continue without compression.\n"; }
 		}
 		$avail{'compress'} = 0;
 	}
@@ -479,7 +479,7 @@ sub checkcommands {
 	if ($debug) { print "DEBUG: checking availability of $mbuffercmd on source...\n"; }
 	$avail{'sourcembuffer'} = `$sourcessh $lscmd $mbuffercmd 2>/dev/null`;
 	if ($avail{'sourcembuffer'} eq '') {
-		print "WARN: $mbuffercmd not available on source $s - sync will continue without source buffering.\n";
+		if (!$quiet) { print "WARN: $mbuffercmd not available on source $s - sync will continue without source buffering.\n"; }
 		$avail{'sourcembuffer'} = 0;
 	} else {
 		$avail{'sourcembuffer'} = 1;
@@ -488,7 +488,7 @@ sub checkcommands {
 	if ($debug) { print "DEBUG: checking availability of $mbuffercmd on target...\n"; }
 	$avail{'targetmbuffer'} = `$targetssh $lscmd $mbuffercmd 2>/dev/null`;
 	if ($avail{'targetmbuffer'} eq '') {
-		print "WARN: $mbuffercmd not available on target $t - sync will continue without target buffering.\n";
+		if (!$quiet) { print "WARN: $mbuffercmd not available on target $t - sync will continue without target buffering.\n"; }
 		$avail{'targetmbuffer'} = 0;
 	} else {
 		$avail{'targetmbuffer'} = 1;
@@ -500,14 +500,14 @@ sub checkcommands {
 		$avail{'localmbuffer'} = `$lscmd $mbuffercmd 2>/dev/null`;
 		if ($avail{'localmbuffer'} eq '') {
 			$avail{'localmbuffer'} = 0;
-			print "WARN: $mbuffercmd not available on local machine - sync will continue without local buffering.\n";
+			if (!$quiet) { print "WARN: $mbuffercmd not available on local machine - sync will continue without local buffering.\n"; }
 		}
 	}
 
 	if ($debug) { print "DEBUG: checking availability of $pvcmd on local machine...\n"; }
 	$avail{'localpv'} = `$lscmd $pvcmd 2>/dev/null`;
 	if ($avail{'localpv'} eq '') {
-		print "WARN: $pvcmd not available on local machine - sync will continue without progress bar.\n";
+		if (!$quiet) { print "WARN: $pvcmd not available on local machine - sync will continue without progress bar.\n"; }
 		$avail{'localpv'} = 0;
 	} else {
 		$avail{'localpv'} = 1;

From 7c68ef5e8f2f491fe7de3b23a53f8b64a026a883 Mon Sep 17 00:00:00 2001
From: Christoph Klaffl <christoph@phreaker.eu>
Date: Sun, 29 Jul 2018 13:16:53 +0200
Subject: [PATCH 03/14] return a non zero exit code if there was a problem
 replicating datasets

---
 syncoid | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/syncoid b/syncoid
index 6c569b2..6453d0f 100755
--- a/syncoid
+++ b/syncoid
@@ -97,6 +97,7 @@ my $targetsudocmd = $targetisroot ? '' : $sudocmd;
 my %avail = checkcommands();
 
 my %snaps;
+my $exitcode = 0;
 
 ## break here to call replication individually so that we ##
 ## can loop across children separately, for recursive     ##
@@ -127,7 +128,7 @@ if ($targethost ne '') {
 	close FH;
 }
 
-exit 0;
+exit $exitcode;
 
 ##############################################################################
 ##############################################################################
@@ -186,6 +187,7 @@ sub syncdataset {
 	# make sure target is not currently in receive.
 	if (iszfsbusy($targethost,$targetfs,$targetisroot)) {
 		warn "Cannot sync now: $targetfs is already target of a zfs receive process.\n";
+		if ($exitcode < 1) { $exitcode = 1; }
 		return 0;
 	}
 
@@ -236,6 +238,7 @@ sub syncdataset {
 			$newsyncsnap = getnewestsnapshot($sourcehost,$sourcefs,$sourceisroot);
 			if ($newsyncsnap eq 0) {
 				warn "CRITICAL: no snapshots exist on source $sourcefs, and you asked for --no-sync-snap.\n";
+				if ($exitcode < 1) { $exitcode = 1; }
 				return 0;
 			}
 		}
@@ -292,6 +295,7 @@ sub syncdataset {
 		# make sure target is (still) not currently in receive.
 		if (iszfsbusy($targethost,$targetfs,$targetisroot)) {
 			warn "Cannot sync now: $targetfs is already target of a zfs receive process.\n";
+			if ($exitcode < 1) { $exitcode = 1; }
 			return 0;
 		}
 		system($synccmd) == 0
@@ -318,6 +322,7 @@ sub syncdataset {
 			# make sure target is (still) not currently in receive.
 			if (iszfsbusy($targethost,$targetfs,$targetisroot)) {
 				warn "Cannot sync now: $targetfs is already target of a zfs receive process.\n";
+				if ($exitcode < 1) { $exitcode = 1; }
 				return 0;
 			}
 
@@ -325,9 +330,12 @@ sub syncdataset {
 			if ($debug) { print "DEBUG: $synccmd\n"; }
 
 			if ($oldestsnap ne $newsyncsnap) {
-				system($synccmd) == 0
-					or warn "CRITICAL ERROR: $synccmd failed: $?";
+				my $ret = system($synccmd);
+				if ($ret != 0) {
+					warn "CRITICAL ERROR: $synccmd failed: $?";
+					if ($exitcode < 1) { $exitcode = 1; }
 					return 0;
+				}
 			} else {
 				if (!$quiet) { print "INFO: no incremental sync needed; $oldestsnap is already the newest available snapshot.\n"; }
 			}
@@ -380,6 +388,7 @@ sub syncdataset {
 		# make sure target is (still) not currently in receive.
 		if (iszfsbusy($targethost,$targetfs,$targetisroot)) {
 			warn "Cannot sync now: $targetfs is already target of a zfs receive process.\n";
+			if ($exitcode < 1) { $exitcode = 1; }
 			return 0;
 		}
 
@@ -910,6 +919,7 @@ sub getmatchingsnapshot {
 	}
 
 	# if we got this far, we failed to find a matching snapshot.
+	if ($exitcode < 2) { $exitcode = 2; }
 
 	print "\n";
 	print "CRITICAL ERROR: Target $targetfs exists but has no snapshots matching with $sourcefs!\n";

From 63eec4994c20d7eb6207f6c6927badf138442f22 Mon Sep 17 00:00:00 2001
From: Christoph Klaffl <christoph@phreaker.eu>
Date: Mon, 30 Jul 2018 22:21:14 +0200
Subject: [PATCH 04/14] don't die on some critical sync errors, but continue to
 replicate all the other datasets. after all is done exit with an error code

---
 syncoid | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/syncoid b/syncoid
index 6453d0f..1ef1506 100755
--- a/syncoid
+++ b/syncoid
@@ -298,8 +298,11 @@ sub syncdataset {
 			if ($exitcode < 1) { $exitcode = 1; }
 			return 0;
 		}
-		system($synccmd) == 0
-			or die "CRITICAL ERROR: $synccmd failed: $?";
+		system($synccmd) == 0 or do {
+			warn "CRITICAL ERROR: $synccmd failed: $?";
+			if ($exitcode < 2) { $exitcode = 2; }
+			return 0;
+		};
 
 		# now do an -I to the new sync snapshot, assuming there were any snapshots
 		# other than the new sync snapshot to begin with, of course - and that we
@@ -359,8 +362,11 @@ sub syncdataset {
 
 		    if (!$quiet) { print "Resuming interrupted zfs send/receive from $sourcefs to $targetfs (~ $disp_pvsize remaining):\n"; }
 		    if ($debug) { print "DEBUG: $synccmd\n"; }
-		    system("$synccmd") == 0
-		        or die "CRITICAL ERROR: $synccmd failed: $?";
+		    system("$synccmd") == 0 or do {
+		        warn "CRITICAL ERROR: $synccmd failed: $?";
+		        if ($exitcode < 2) { $exitcode = 2; }
+		        return 0;
+		    };
 
 		    # a resumed transfer will only be done to the next snapshot,
 		    # so do an normal sync cycle
@@ -416,8 +422,11 @@ sub syncdataset {
 
 			if (!$quiet) { print "Sending incremental $sourcefs\@$matchingsnap ... $newsyncsnap (~ $disp_pvsize):\n"; }
 			if ($debug) { print "DEBUG: $synccmd\n"; }
-			system("$synccmd") == 0
-				or die "CRITICAL ERROR: $synccmd failed: $?";
+			system("$synccmd") == 0 or do {
+				warn "CRITICAL ERROR: $synccmd failed: $?";
+				if ($exitcode < 2) { $exitcode = 2; }
+				return 0;
+			};
 
 			# restore original readonly value to target after sync complete
 				# dyking this functionality out for the time being due to buggy mount/unmount behavior

From 9668567a870def5418032fb922d3a27a643059fa Mon Sep 17 00:00:00 2001
From: Christoph Klaffl <christoph@phreaker.eu>
Date: Mon, 30 Jul 2018 22:53:48 +0200
Subject: [PATCH 05/14] continue replication on more critical errors

---
 syncoid | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/syncoid b/syncoid
index 1ef1506..73205ce 100755
--- a/syncoid
+++ b/syncoid
@@ -233,6 +233,10 @@ sub syncdataset {
 		if (!defined $args{'no-sync-snap'}) {
 			# create a new syncoid snapshot on the source filesystem.
 			$newsyncsnap = newsyncsnap($sourcehost,$sourcefs,$sourceisroot);
+			if (!$newsyncsnap) {
+				# we already whined about the error
+				return 0;
+			}
 		} else {
 			# we don't want sync snapshots created, so use the newest snapshot we can find.
 			$newsyncsnap = getnewestsnapshot($sourcehost,$sourcefs,$sourceisroot);
@@ -267,6 +271,11 @@ sub syncdataset {
 		}
 		my $oldestsnap = getoldestsnapshot(\%snaps);
 		if (! $oldestsnap) {
+			if (defined ($args{'no-sync-snap'}) ) {
+				# we already whined about the missing snapshots
+				return 0;
+			}
+
 			# getoldestsnapshot() returned false, so use new sync snapshot
 			if ($debug) { print "DEBUG: getoldestsnapshot() returned false, so using $newsyncsnap.\n"; }
 			$oldestsnap = $newsyncsnap;
@@ -752,7 +761,7 @@ sub getoldestsnapshot {
 	# must not have had any snapshots on source - luckily, we already made one, amirite?
 	if (defined ($args{'no-sync-snap'}) ) {
 		# well, actually we set --no-sync-snap, so no we *didn't* already make one. Whoops.
-		die "CRIT: --no-sync-snap is set, and getoldestsnapshot() could not find any snapshots on source!\n";
+		warn "CRIT: --no-sync-snap is set, and getoldestsnapshot() could not find any snapshots on source!\n";
 	}
 	return 0;
 }
@@ -774,6 +783,7 @@ sub getnewestsnapshot {
 		#        we also probably need an argument to mute this WARN, for people who deliberately exclude
 		#        datasets from recursive replication this way.
 		warn "WARN: --no-sync-snap is set, and getnewestsnapshot() could not find any snapshots on source for current dataset. Continuing.\n";
+		if ($exitcode < 2) { $exitcode = 2; }
 	}
 	return 0;
 }
@@ -961,8 +971,12 @@ sub newsyncsnap {
 	my %date = getdate();
 	my $snapname = "syncoid\_$identifier$hostid\_$date{'stamp'}";
 	my $snapcmd = "$rhost $mysudocmd $zfscmd snapshot $fsescaped\@$snapname\n";
-	system($snapcmd) == 0
-		or die "CRITICAL ERROR: $snapcmd failed: $?";
+	system($snapcmd) == 0 or do {
+		warn "CRITICAL ERROR: $snapcmd failed: $?";
+		if ($exitcode < 2) { $exitcode = 2; }
+		return 0;
+	};
+
 	return $snapname;
 }
 

From fb8edad885522040369c6ab95edfbb922fb6901d Mon Sep 17 00:00:00 2001
From: Attie Grande <attie@attie.co.uk>
Date: Fri, 3 Aug 2018 09:13:35 +0100
Subject: [PATCH 06/14] compression warnings are no longer hidden by --quiet

---
 syncoid | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/syncoid b/syncoid
index aec99cd..85d5e16 100755
--- a/syncoid
+++ b/syncoid
@@ -452,13 +452,13 @@ sub checkcommands {
 
 	if ($avail{'sourcecompress'} eq '') {
 		if ($compressargs{'rawcmd'} ne '') {
-			if (!$quiet) { print "WARN: $compressargs{'rawcmd'} not available on source $s- sync will continue without compression.\n"; }
+			print "WARN: $compressargs{'rawcmd'} not available on source $s- sync will continue without compression.\n";
 		}
 		$avail{'compress'} = 0;
 	}
 	if ($avail{'targetcompress'} eq '') {
 		if ($compressargs{'rawcmd'} ne '') {
-			if (!$quiet) { print "WARN: $compressargs{'rawcmd'} not available on target $t - sync will continue without compression.\n"; }
+			print "WARN: $compressargs{'rawcmd'} not available on target $t - sync will continue without compression.\n";
 		}
 		$avail{'compress'} = 0;
 	}
@@ -471,7 +471,7 @@ sub checkcommands {
 	# corner case - if source AND target are BOTH remote, we have to check for local compress too
 	if ($sourcehost ne '' && $targethost ne '' && $avail{'localcompress'} eq '') {
 		if ($compressargs{'rawcmd'} ne '') {
-			if (!$quiet) { print "WARN: $compressargs{'rawcmd'} not available on local machine - sync will continue without compression.\n"; }
+			print "WARN: $compressargs{'rawcmd'} not available on local machine - sync will continue without compression.\n";
 		}
 		$avail{'compress'} = 0;
 	}

From 39d1fd38c1edd52f45b44707beabe32e3a20900d Mon Sep 17 00:00:00 2001
From: Attie Grande <attie@attie.co.uk>
Date: Fri, 5 Jan 2018 21:54:06 +0000
Subject: [PATCH 07/14] added ability to skip datasets... simply set
 syncoid:no-sync=true

---
 syncoid | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/syncoid b/syncoid
index 6c569b2..8adaa87 100755
--- a/syncoid
+++ b/syncoid
@@ -183,6 +183,11 @@ sub syncdataset {
 
 	if ($debug) { print "DEBUG: syncing source $sourcefs to target $targetfs.\n"; }
 
+	if (getzfsvalue($sourcehost,$sourcefs,$sourceisroot,'syncoid:no-sync') eq 'true') {
+		print "Skipping dataset (syncoid:nosync=true): $sourcefs...\n";
+		return 0;
+	}
+
 	# make sure target is not currently in receive.
 	if (iszfsbusy($targethost,$targetfs,$targetisroot)) {
 		warn "Cannot sync now: $targetfs is already target of a zfs receive process.\n";

From 22c137627a9a923807565dff01794d9d3775e767 Mon Sep 17 00:00:00 2001
From: Attie Grande <attie@attie.co.uk>
Date: Sat, 6 Jan 2018 10:15:30 +0000
Subject: [PATCH 08/14] updated doc for syncoid:no-sync

---
 README.md | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/README.md b/README.md
index e359886..ba325e6 100644
--- a/README.md
+++ b/README.md
@@ -118,6 +118,14 @@ If ZFS supports resumeable send/receive streams on both the source and target th
 
 As of 1.4.18, syncoid also automatically supports and enables resume of interrupted replication when both source and target support this feature.
 
+##### Syncoid Dataset Properties
+
++ syncoid:no-sync
+
+  Setting this to `true` will prevent the dataset from being handled by syncoid in _any_ way - it will be skipped. This can be useful for preventing certain datasets from being transferred when recursively handling a tree.
+
+  Note that this will also prevent syncoid from handling the dataset if given explicitly on the command line.
+
 ##### Syncoid Command Line Options
 
 + [source]

From b02b9a582bd3f92c01f16c954add64a78e647896 Mon Sep 17 00:00:00 2001
From: Attie Grande <attie@attie.co.uk>
Date: Sat, 6 Jan 2018 10:43:30 +0000
Subject: [PATCH 09/14] now obeying --quiet, and added 'INFO: ' prefix to skip
 message

---
 syncoid | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/syncoid b/syncoid
index 8adaa87..2201f41 100755
--- a/syncoid
+++ b/syncoid
@@ -184,7 +184,7 @@ sub syncdataset {
 	if ($debug) { print "DEBUG: syncing source $sourcefs to target $targetfs.\n"; }
 
 	if (getzfsvalue($sourcehost,$sourcefs,$sourceisroot,'syncoid:no-sync') eq 'true') {
-		print "Skipping dataset (syncoid:nosync=true): $sourcefs...\n";
+		if (!$quiet) { print "INFO: Skipping dataset (syncoid:nosync=true): $sourcefs...\n"; }
 		return 0;
 	}
 

From c188e47a6da2d8ee2857a8eb1c0400bc78fc7a53 Mon Sep 17 00:00:00 2001
From: Attie Grande <attie@attie.co.uk>
Date: Fri, 9 Mar 2018 15:15:06 +0000
Subject: [PATCH 10/14] inverted sync/no-sync logic

---
 syncoid | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/syncoid b/syncoid
index 2201f41..20c0853 100755
--- a/syncoid
+++ b/syncoid
@@ -183,8 +183,8 @@ sub syncdataset {
 
 	if ($debug) { print "DEBUG: syncing source $sourcefs to target $targetfs.\n"; }
 
-	if (getzfsvalue($sourcehost,$sourcefs,$sourceisroot,'syncoid:no-sync') eq 'true') {
-		if (!$quiet) { print "INFO: Skipping dataset (syncoid:nosync=true): $sourcefs...\n"; }
+	if (getzfsvalue($sourcehost,$sourcefs,$sourceisroot,'syncoid:sync') eq 'false') {
+		if (!$quiet) { print "INFO: Skipping dataset (syncoid:sync=false): $sourcefs...\n"; }
 		return 0;
 	}
 

From f0a37310a54b5e421264d05a02ad226a1409bb98 Mon Sep 17 00:00:00 2001
From: Attie Grande <attie@attie.co.uk>
Date: Fri, 9 Mar 2018 15:18:03 +0000
Subject: [PATCH 11/14] implemented sync true/false/${HOSTS} filtering

---
 syncoid | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/syncoid b/syncoid
index 20c0853..7877723 100755
--- a/syncoid
+++ b/syncoid
@@ -183,9 +183,20 @@ sub syncdataset {
 
 	if ($debug) { print "DEBUG: syncing source $sourcefs to target $targetfs.\n"; }
 
-	if (getzfsvalue($sourcehost,$sourcefs,$sourceisroot,'syncoid:sync') eq 'false') {
+	my $sync = getzfsvalue($sourcehost,$sourcefs,$sourceisroot,'syncoid:sync');
+
+	if ($sync eq 'true' || $sync eq '-') {
+		# definitely sync this dataset - if a host is called 'true' or '-', then you're special
+	} elsif ($sync eq 'false') {
 		if (!$quiet) { print "INFO: Skipping dataset (syncoid:sync=false): $sourcefs...\n"; }
 		return 0;
+	} else {
+		my $hostid = hostname();
+		my @hosts = split(/,/,$sync);
+		if (!(grep $hostid eq $_, @hosts)) {
+			if (!$quiet) { print "INFO: Skipping dataset (syncoid:sync doesn't include $hostid): $sourcefs...\n"; }
+			return 0;
+		}
 	}
 
 	# make sure target is not currently in receive.

From a4e490f430b73454422c28254012a3328f9bbe98 Mon Sep 17 00:00:00 2001
From: Attie Grande <attie@attie.co.uk>
Date: Fri, 9 Mar 2018 15:28:39 +0000
Subject: [PATCH 12/14] updated documentation for the syncoid:sync property's
 new behaviour

---
 README.md | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index ba325e6..bb6ec89 100644
--- a/README.md
+++ b/README.md
@@ -120,11 +120,27 @@ As of 1.4.18, syncoid also automatically supports and enables resume of interrup
 
 ##### Syncoid Dataset Properties
 
-+ syncoid:no-sync
++ syncoid:sync
 
-  Setting this to `true` will prevent the dataset from being handled by syncoid in _any_ way - it will be skipped. This can be useful for preventing certain datasets from being transferred when recursively handling a tree.
+  Available values:
 
-  Note that this will also prevent syncoid from handling the dataset if given explicitly on the command line.
+  + `true` (default if unset)
+
+    This dataset will be synchronised to all hosts.
+
+  + `false`
+
+    This dataset will not be synchronised to any hosts - it will be skipped. This can be useful for preventing certain datasets from being transferred when recursively handling a tree.
+
+  + `host1,host2,...`
+
+    A comma seperated list of hosts. This dataset will only be synchronised by hosts listed in the property.
+
+    _Note_: this check is performed by the host running `syncoid`, thus the local hostname must be present for inclusion during a push operation // the remote hostname must be present for a pull.
+
+  _Note_: this will also prevent syncoid from handling the dataset if given explicitly on the command line.
+
+  _Note_: syncing a child of a no-sync dataset will currently result in a critical error
 
 ##### Syncoid Command Line Options
 

From 60b2dedc456a8464f86cf75dacfe62c0b6410dbc Mon Sep 17 00:00:00 2001
From: Attie Grande <attie@attie.co.uk>
Date: Mon, 6 Aug 2018 14:07:58 +0100
Subject: [PATCH 13/14] fixed typo

---
 README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/README.md b/README.md
index bb6ec89..8c05fb3 100644
--- a/README.md
+++ b/README.md
@@ -134,7 +134,7 @@ As of 1.4.18, syncoid also automatically supports and enables resume of interrup
 
   + `host1,host2,...`
 
-    A comma seperated list of hosts. This dataset will only be synchronised by hosts listed in the property.
+    A comma separated list of hosts. This dataset will only be synchronised by hosts listed in the property.
 
     _Note_: this check is performed by the host running `syncoid`, thus the local hostname must be present for inclusion during a push operation // the remote hostname must be present for a pull.
 

From d0ba0bc284bb92a8f0e63cfbd773e8c61e175973 Mon Sep 17 00:00:00 2001
From: Attie Grande <attie@attie.co.uk>
Date: Mon, 6 Aug 2018 14:16:25 +0100
Subject: [PATCH 14/14] handled empty syncoid:sync property - behaves like
 unset

---
 README.md | 4 +++-
 syncoid   | 3 ++-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/README.md b/README.md
index 8c05fb3..b833dec 100644
--- a/README.md
+++ b/README.md
@@ -140,7 +140,9 @@ As of 1.4.18, syncoid also automatically supports and enables resume of interrup
 
   _Note_: this will also prevent syncoid from handling the dataset if given explicitly on the command line.
 
-  _Note_: syncing a child of a no-sync dataset will currently result in a critical error
+  _Note_: syncing a child of a no-sync dataset will currently result in a critical error.
+
+  _Note_: empty properties will be handled as if they were unset.
 
 ##### Syncoid Command Line Options
 
diff --git a/syncoid b/syncoid
index 7877723..fa00751 100755
--- a/syncoid
+++ b/syncoid
@@ -185,7 +185,8 @@ sub syncdataset {
 
 	my $sync = getzfsvalue($sourcehost,$sourcefs,$sourceisroot,'syncoid:sync');
 
-	if ($sync eq 'true' || $sync eq '-') {
+	if ($sync eq 'true' || $sync eq '-' || $sync eq '') {
+		# empty is handled the same as unset (aka: '-')
 		# definitely sync this dataset - if a host is called 'true' or '-', then you're special
 	} elsif ($sync eq 'false') {
 		if (!$quiet) { print "INFO: Skipping dataset (syncoid:sync=false): $sourcefs...\n"; }