diff --git a/bundles/zfs/files/zfs-modprobe.conf b/bundles/zfs/files/zfs-modprobe.conf
index 256c971..1f44bc3 100644
--- a/bundles/zfs/files/zfs-modprobe.conf
+++ b/bundles/zfs/files/zfs-modprobe.conf
@@ -1,6 +1,6 @@
 <%
-    arc_max_mb = node.metadata.get('zfs/module_options/zfs_arc_max_mb', 1024)
+    arc_max_gb = node.metadata.get('zfs/module_options/zfs_arc_max_gb', 1)
 %>\
-% if arc_max_mb != 0:
-options zfs zfs_arc_max=${arc_max_mb * 1024 * 1024}
+% if arc_max_gb > 0:
+options zfs zfs_arc_max=${arc_max_gb * 1024 * 1024 * 1024}
 % endif
diff --git a/nodes/home/nas.py b/nodes/home/nas.py
index 08e8a13..5006896 100644
--- a/nodes/home/nas.py
+++ b/nodes/home/nas.py
@@ -188,6 +188,9 @@ nodes['home.nas'] = {
             },
         },
         'zfs': {
+            'module_options': {
+                'zfs_arc_max_gb': 8,
+            },
             'pools': {
                 # Configured manually. Don't touch!
                 'storage': {
diff --git a/nodes/rx300.py b/nodes/rx300.py
index 06a12bc..dec7a17 100644
--- a/nodes/rx300.py
+++ b/nodes/rx300.py
@@ -71,7 +71,7 @@ nodes['rx300'] = {
         },
         'zfs': {
             'module_options': {
-                'zfs_arc_max_mb': 16384, # 16GB
+                'zfs_arc_max_gb': 16,
             },
             'pools': {
                 'tank': {