diff --git a/frontend-modern/src/components/Dashboard/GuestRow.tsx b/frontend-modern/src/components/Dashboard/GuestRow.tsx
index f72e8096b..4c3bcd39a 100644
--- a/frontend-modern/src/components/Dashboard/GuestRow.tsx
+++ b/frontend-modern/src/components/Dashboard/GuestRow.tsx
@@ -69,6 +69,8 @@ export function GuestRow(props: GuestRowProps) {
   });
   const diskPercent = createMemo(() => {
     if (!props.guest.disk || props.guest.disk.total === 0) return 0;
+    // Check if usage is -1 (unknown/no guest agent)
+    if (props.guest.disk.usage === -1) return -1;
     return (props.guest.disk.used / props.guest.disk.total) * 100;
   });
 
@@ -185,7 +187,7 @@ export function GuestRow(props: GuestRowProps) {
       {/* Disk */}
       <td class="p-1 px-2 w-[140px]">
         <Show 
-          when={props.guest.disk && props.guest.disk.total > 0}
+          when={props.guest.disk && props.guest.disk.total > 0 && diskPercent() !== -1}
           fallback={<span class="text-gray-400 text-sm">-</span>}
         >
           <MetricBar 
diff --git a/internal/monitoring/monitor.go b/internal/monitoring/monitor.go
index 6fc02147e..d8ddf0dc8 100644
--- a/internal/monitoring/monitor.go
+++ b/internal/monitoring/monitor.go
@@ -958,6 +958,12 @@ func (m *Monitor) pollVMsAndContainersEfficient(ctx context.Context, instanceNam
 			diskFree := diskTotal - diskUsed
 			diskUsage := safePercentage(float64(diskUsed), float64(diskTotal))
 			
+			// If VM shows 0 disk usage but has allocated disk, it's likely guest agent issue
+			// Set to -1 to indicate "unknown" rather than showing misleading 0%
+			if res.Type == "qemu" && diskUsed == 0 && diskTotal > 0 && res.Status == "running" {
+				diskUsage = -1
+			}
+			
 			// For running VMs, try to get filesystem info from guest agent
 			if res.Status == "running" {
 				// First check if agent is enabled by getting VM status
@@ -1355,6 +1361,12 @@ func (m *Monitor) pollVMsWithNodes(ctx context.Context, instanceName string, cli
 			diskFree := diskTotal - diskUsed
 			diskUsage := safePercentage(float64(diskUsed), float64(diskTotal))
 			
+			// If VM shows 0 disk usage but has allocated disk, it's likely guest agent issue
+			// Set to -1 to indicate "unknown" rather than showing misleading 0%
+			if diskUsed == 0 && diskTotal > 0 && vm.Status == "running" {
+				diskUsage = -1
+			}
+			
 			// If VM has guest agent enabled and is running, try to get filesystem info
 			if vm.Agent > 0 && vm.Status == "running" {
 				log.Debug().