From d527762766738081c540e1db7d8f09bbf0ba8066 Mon Sep 17 00:00:00 2001
From: Abhisar Sinha <63767682+abh1sar@users.noreply.github.com>
Date: Tue, 17 Mar 2026 07:35:38 +0530
Subject: [PATCH] Fix backup of stopped VMs by allowing multiple connections.

---
 .../resource/wrapper/LibvirtStartNBDServerCommandWrapper.java | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/wrapper/LibvirtStartNBDServerCommandWrapper.java b/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/wrapper/LibvirtStartNBDServerCommandWrapper.java
index fb532fd2a9a..56d5945ced1 100644
--- a/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/wrapper/LibvirtStartNBDServerCommandWrapper.java
+++ b/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/wrapper/LibvirtStartNBDServerCommandWrapper.java
@@ -68,8 +68,10 @@ public class LibvirtStartNBDServerCommandWrapper extends CommandWrapper<StartNBD
         }
 
         String socketName = "/tmp/imagetransfer/" + socket + ".sock";
+        // --persistent: Don't stop the service when the last client disconnects.
+        // --shared=NUM: Allow up to NUM clients to share the device (default 1), 0 for unlimited. Number of parallel connections is managed by the image server.
         String systemdRunCmd = String.format(
-                "systemd-run --unit=%s --property=Restart=no qemu-nbd --export-name %s --socket %s --persistent %s %s %s",
+                "systemd-run --unit=%s --property=Restart=no qemu-nbd --export-name %s --socket %s --persistent --shared=0 %s %s %s",
                 unitName,
                 exportName,
                 socketName,