diff --git a/share/common.nix b/share/common.nix
index fd0171e..f66d946 100644
--- a/share/common.nix
+++ b/share/common.nix
@@ -127,10 +127,13 @@ in
   # tune the ZFS pool for NVMe
   system.activationScripts.zfsTuning = {
     text = ''
-      # only one level of metadata caching
+      # only one level of caching
       ${pkgs.zfs}/bin/zfs set primarycache=all zpool
       ${pkgs.zfs}/bin/zfs set secondarycache=none zpool
 
+      # I have backups and no real databases
+      ${pkgs.zfs}/bin/zfs set sync=disabled zpool
+
       # use allow direct IO
       ${pkgs.zfs}/bin/zfs set direct=standard zpool
     '';