diff --git a/src/PVE/Storage/LVMPlugin.pm b/src/PVE/Storage/LVMPlugin.pm
index 45e99db..74366c3 100644
--- a/src/PVE/Storage/LVMPlugin.pm
+++ b/src/PVE/Storage/LVMPlugin.pm
@@ -11,7 +11,6 @@ use PVE::Storage::Plugin;
 use PVE::JSONSchema qw(get_standard_option);
 
 use PVE::Storage::Common;
-use PVE::SafeSyslog;
 
 use JSON;
 
@@ -401,6 +400,8 @@ sub options {
         tagged_only => { optional => 1 },
         bwlimit => { optional => 1 },
         'snapshot-as-volume-chain' => { optional => 1 },
+        chunksize => { optional => 1 },
+        'chunk-percentage' => { optional => 1 },
     };
 }
 
@@ -586,7 +587,6 @@ my sub lvm_qcow2_format {
     };
     if ($backing_snap) {
         my $backing_volname = get_snap_name($class, $name, $backing_snap);
-        # TODO: make this variable a check box when taking a snapshot
         PVE::Storage::Common::qemu_img_create_qcow2_backed(
             $path, $backing_volname, $fmt, $options, $thin,
         );
@@ -634,8 +634,12 @@ my sub alloc_lvm_image {
 
     my $free = int($vgs->{$vg}->{free});
     my $lvmsize;
-    if ($backing_snap) {
-        $lvmsize = 2.5 * 1024 * 1024;
+
+    # FIX: make this variable a check box when taking a snapshot
+    # right now all snapshots are created thin for testing purposes
+    my $thin = $backing_snap ? 1 : 0;
+    if ($thin) {
+        $lvmsize = 2 * 1024 * 1024;
     } else {
         $lvmsize = calculate_lvm_size($size, $fmt, $backing_snap);
     }
@@ -649,7 +653,6 @@ my sub alloc_lvm_image {
 
     return if $fmt ne 'qcow2';
 
-    my $thin = $backing_snap ? 1 : 0;
     #format the lvm volume with qcow2 format
     eval { lvm_qcow2_format($class, $storeid, $scfg, $name, $fmt, $backing_snap, $size, $thin) };
     if ($@) {
@@ -952,10 +955,7 @@ sub volume_underlay_resize {
     my ($class, $scfg, $storeid, $volname, $backing_snap) = @_;
 
     my ($format) = ($class->parse_volname($volname))[6];
-    # extend underlay lv
-    # need to check if next size is going to surpass the qcow2 virtual size
-    # if so need to calculate the final size with calculate_lvm_size
-    # by using qemu_img_info
+
     my $path = $class->filesystem_path($scfg, $volname);
     my $json = PVE::Storage::Common::qemu_img_info($path, undef, 10, 0);
     my $json_decode = eval { decode_json($json) };
@@ -963,18 +963,14 @@ sub volume_underlay_resize {
         die "Can't decode qemu snapshot list. Invalid JSON: $@\n";
     }
 
-    my $virtual_size = int($json_decode->{'virtual-size'} / 1024);
-    syslog("info", "current qcow2 virtual size $virtual_size KiB\n");
+    my $virtual_size = $json_decode->{'virtual-size'} / 1024;
 
     my $underlay_size = lv_size($path, 10);
-    syslog("info", "current underlay size $underlay_size B\n ");
-    # FIX: 1GiB increment needs to change to a configurable var $scfg->{chunk_size}
-    my $updated_underlay_size = ($underlay_size + (1024 * 1024 * 1024)) / 1024;
-    syslog("info", "current updated underlay size $updated_underlay_size KiB\n");
+
+    my $updated_underlay_size = ($underlay_size + $scfg->{chunksize}) / 1024;
     $updated_underlay_size = calculate_lvm_size($virtual_size, $format, $backing_snap)
         if $updated_underlay_size >= $virtual_size;
 
-    syslog("info", "current updated underlay size $updated_underlay_size KiB\n");
     my $lvmsize = "${updated_underlay_size}k";
     lv_extend($class, $scfg, $storeid, $lvmsize, $path);
 
diff --git a/src/PVE/Storage/Plugin.pm b/src/PVE/Storage/Plugin.pm
index 6865b08..9bc60f2 100644
--- a/src/PVE/Storage/Plugin.pm
+++ b/src/PVE/Storage/Plugin.pm
@@ -228,6 +228,20 @@ my $defaultData = {
             default => 0,
             optional => 1,
         },
+        chunksize => {
+            type => 'integer',
+            description => 'The chunksize in Bytes to define the write threshold'
+                . 'of thin disks on thick storage.',
+            default => 1073741824, # 1 GiB
+            optional => 1,
+        },
+        'chunk-percentage' => {
+            type => 'number',
+            description => 'The percentage of written disk to define the write'
+                . 'threshold.',
+            default => 0.5,
+            optional => 1,
+        },
     },
 };