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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"KVM: Live migration of SSVM fails with dedicated VLAN","articleBody":"### problem\n\n Live migration of SSVMs  fails on KVM when the zone has a dedicated storage network IP range configured with a VLAN. The destination agent never creates the storage VLAN bridge during   \n  PrepareForMigrationCommand, so libvirt cannot find the bridge from the source VM's XML and aborts\n\nThis is because the storage network is created with broadcast_domain_type: Native and broadcastUri: storage://\u003cstorage_vlan\u003e\nAnd In BridgeVifDriver.createStorageVnetBridgeIfNeeded():                                                                                                                                                                    \n```\n                                                                                                                                                                                                                           \n  if (!Networks.BroadcastDomainType.Storage.equals(nic.getBroadcastType()) || nic.getBroadcastUri() == null) {                                                                                                             \n      return storageBrName;  // exits early and bridge is never created                                                                                                                                                         \n  }    \n```\n\nthe above check causes it to exit early and never create the bridge on the destination host\n\n\n\n### versions\n\n4.20.3 onward\n\n### The steps to reproduce the bug\n\nSteps to Reproduce                                                                                                                                                                                                       \n                                                                                                                                                                                                                           \n  1. Create a zone with KVM hosts                                                                                                                                                                                      \n  2. Add a pod management network IP range (untagged)                                                                                                                                                                      \n  3. Add a Storage Network IP Range to the pod with a non-zero VLAN ID (storage_vlan)                                                                                                                                                                                                                                                                                  \n  4. Start the zone - system VMs are created; confirm br\u003cnic\u003e-\u003cstorage_vlan\u003e exists on the source host                                                                                                                     \n  5. Attempt live migration of the Secondary Storage VM to the other host                                                                                                                                                  \n  6. Migration fails with Cannot get interface MTU on 'br\u003cnic\u003e-\u003cstorage_vlan\u003e': No such device                         \n\n\n### What to do about it?\n\n_No response_","author":{"url":"https://github.com/Pearl1594","@type":"Person","name":"Pearl1594"},"datePublished":"2026-06-08T18:49:42.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":0},"url":"https://github.com/13378/cloudstack/issues/13378"}