diff --git a/protogeni/scripts/mondbd.in b/protogeni/scripts/mondbd.in
index 66437a247e0cee7917f737a60f83877e51cf7df4..3b4c669abbde383827e30d8a2888b6a88ae5ae92 100755
--- a/protogeni/scripts/mondbd.in
+++ b/protogeni/scripts/mondbd.in
@@ -272,6 +272,31 @@ while (1) {
     my $ts = time() . "000000";
     my $expire = ( time() - 24 * 60 * 60 ) . "000000";
 
+    # Trim old timeseries data.
+    foreach my $table (
+	"ops_interface_rx_bps",
+	"ops_interface_rx_dps",
+	"ops_interface_rx_eps",
+	"ops_interface_rx_pps",
+	"ops_interface_tx_bps",
+	"ops_interface_tx_dps",
+	"ops_interface_tx_eps",
+	"ops_interfacevlan_rx_bps",
+	"ops_interfacevlan_rx_dps",
+	"ops_interfacevlan_rx_eps",
+	"ops_interfacevlan_rx_pps",
+	"ops_interfacevlan_tx_bps",
+	"ops_interfacevlan_tx_dps",
+	"ops_interfacevlan_tx_eps",
+	"ops_interfacevlan_tx_pps",
+	"ops_node_cpu_util",
+	"ops_node_disk_part_max_used",
+	"ops_node_mem_used_kb",
+	"ops_node_num_vms_allocated",
+	"ops_node_swap_free" ) {
+	emdbi::DBQueryWarnN( $db, "DELETE FROM $table WHERE ts < $expire" );
+    }    
+    
     # Add the local CM.
     # FIXME would be nice to add routable_ip_poolsize
     emdbi::DBQueryWarnN( $db, "LOCK TABLES ops_aggregate WRITE" );