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    xcp-ng server crashed/rebooted due to issues with drbd/linstor?

    Scheduled Pinned Locked Moved Unsolved XOSTOR
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    • J Offline
      Jonathon @Jonathon
      last edited by Jonathon

      Happens at around the same time. Which point to something on a schedule, and I think it has been found.

      TLDR; It looks like velero backup is hitting the hosts too fast and a possible synchronization bug causes a host to crash.
      I have attempted to slow down velero with the following helm chart value change. Will see if it happens again.

      configuration:
        # Lowers API call velocity to stagger volume Create/Delete cycles
        clientQPS: 3
        clientBurst: 5
        
        # Forces serial execution across volume structures, preventing concurrent lifecycle operations
        itemBlockWorkerCount: 1
      

      I have all the logs in loki, would it be possible for someone to look at this and let me know what other logs are needed to attempt to identify some issue with drbd?


      Timeline of crash

      On Saturday, July 4, 2026, at 23:16:03 PDT, xcp-ng host ovbh-pprod-xen04 suffered a hard kernel panic. The crash was caused by an asynchronous race condition within the DRBD kernel module.
      It looks like this happens during the openvas velero backup. This crash has been happening at the exact same time of day when it crashes. So far this is the only thing I can find happening during this time.

      Started:    2026-07-04 23:15:00 -0700 PDT
      Completed:  2026-07-04 23:17:33 -0700 PDT
      

      Stage 1: Backup Initialization & Storage Provisioning Burst

      Timestamp: 23:15:17 - 23:15:26 PDT

      Velero starts the openvas-daily-20260705061500 snapshot which has PVC volumes (gvmd-pvc, openvas-pvc, psql-pvc). The linstor-csi-controller issues volume creation calls. Linstor establishes metadata across the cluster nodes, provisioning device structures and setting up three-way replication mappings across xen01, xen02, and xen05. It then dynamically drops xen02 and redistributes the active target allocation mirror directly onto xen04 for some reason.

      2026-07-04T23:15:17-07:00 {"time":"2026-07-05T02:15:17.684469063-04:00","stream":"stderr","message":"I0705 06:15:17.683982      69 connection.go:264] \"GRPC call\" method=\"/csi.v1.Controller/CreateVolume\" ... name=\"pvc-385f674a-3dcd-4cfb-8f4d-e4a7157becd1\""}
      2026-07-04T23:15:17-07:00 2026-07-05 02:15:17.723 [grizzly-http-server-19] INFO  LINSTOR/Controller/3de0de SYSTEM - Resource definition created pvc-385f674a-3dcd-4cfb-8f4d-e4a7157becd1
      2026-07-04T23:15:18-07:00 2026-07-05 02:15:18.811 [MainWorkerPool-1] INFO  LINSTOR/Controller/00e49b SYSTEM - ACR: Created resource 'pvc-385f674a-3dcd-4cfb-8f4d-e4a7157becd1' on 'ovbh-pprod-xen01'
      2026-07-04T23:15:20-07:00 2026-07-05 02:15:20.983 [MainWorkerPool-2] INFO  LINSTOR/Controller/00da44 SYSTEM - ACR: Created resource 'pvc-385f674a-3dcd-4cfb-8f4d-e4a7157becd1' on 'ovbh-pprod-xen02'
      2026-07-04T23:15:22-07:00 2026-07-05 02:15:22.516 [MainWorkerPool-16] INFO  LINSTOR/Controller/00dfdd SYSTEM - ACR: Created resource 'pvc-385f674a-3dcd-4cfb-8f4d-e4a7157becd1' on 'ovbh-pprod-xen04'
      2026-07-04T23:15:23-07:00 2026-07-05 02:15:23.294 [MainWorkerPool-12] INFO  LINSTOR/Controller/00dcb8 SYSTEM - Resource deleted [ovbh-pprod-xen02]/pvc-385f674a-3dcd-4cfb-8f4d-e4a7157becd1
      2026-07-04T23:15:26-07:00 2026-07-05 02:15:26.027 [MainWorkerPool-16] INFO  LINSTOR/Controller/00be18 SYSTEM - ACR: Created resource 'pvc-385f674a-3dcd-4cfb-8f4d-e4a7157becd1' on 'ovbh-vprod-k8s01-worker03.floatplane.com'
      

      Stage 2: Rapid Backup Job Completion & Teardown Execution

      Timestamp: 23:15:38 - 23:16:01 PDT

      The temporary target volume (openvas-pvc) completes its read stream sequence inside a brief 14-second operation due to a minuscule dataset size (5,540 bytes). The PersistentVolume state drops to Released. Velero instantly sends a container cleanup execution sequence down the line. The Linstor CSI controller catches the drop and issues an immediate DeleteResource directive to all replication satellites, commanding xen04 to disconnect the live disk configuration mapping.

      2026-07-04T23:15:38-07:00 {"time":"2026-07-05T02:15:38.099681495-04:00","stream":"stdout","message":"time=\"2026-07-05T06:15:38Z\" level=info msg=\"Received event for data path ... reason: SuccessfulAttachVolume ...\""}
      2026-07-04T23:15:52-07:00 {"time":"2026-07-05T02:15:52.97309346-04:00","stream":"stderr","message":"I0705 06:15:52.972697 69 controller.go:1316] \"shouldDelete is true\" PV=\"pvc-385f674a-3dcd-4cfb-8f4d-e4a7157becd1\""}
      2026-07-04T23:15:56-07:00 {"time":"2026-07-05T02:15:56.223202404-04:00","stream":"stderr","message":"I0705 06:15:56.222906 1 reconciler.go:279] \"attacherDetacher.DetachVolume started\" node=\"ovbh-vprod-k8s01-worker03.floatplane.com\""}
      2026-07-04T23:15:59-07:00 {"time":"2026-07-05T02:15:59.977217319-04:00","stream":"stderr","message":"I0705 06:15:59.976833 69 connection.go:264] \"GRPC call\" method=\"/csi.v1.Controller/DeleteVolume\" request=\"{\\\"volume_id\\\":\\\"pvc-385f674a-3dcd-4cfb-8f4d-e4a7157becd1\\\"}\""}
      2026-07-04T23:16:00-07:00 2026-07-05 02:16:00.147 [grizzly-http-server-19] INFO  LINSTOR/Controller/864b2a SYSTEM - Deleting resource ovbh-pprod-xen01/pvc-385f674a-3dcd-4cfb-8f4d-e4a7157becd1
      2026-07-04T23:16:00-07:00 2026-07-05 02:16:00.245 [MainWorkerPool-3] INFO  LINSTOR/Controller/00e4cf SYSTEM - Toggle Disk on ovbh-pprod-xen01/pvc-385f674a-3dcd-4cfb-8f4d-e4a7157becd1 removing disk
      2026-07-04T23:16:01-07:00 2026-07-05 02:16:01.558 [grizzly-http-server-20] INFO  LINSTOR/Controller/e89b52 SYSTEM - Deleting resource ovbh-pprod-xen04/pvc-385f674a-3dcd-4cfb-8f4d-e4a7157becd1
      

      Stage 3: Memory Teardown, GPF, and Hard Kernel Panic

      Timestamp: 23:16:03 - 23:16:05 PDT

      As xen04 unconfigures the storage resource footprint, the unconfigure worker frees up metadata allocation tree parameters. Simultaneously, the connection receiver thread executes an un-serialized bit-counting function scanning the replication tracking context. The receiver thread pulls a stale pointer reference, hitting unmapped virtual memory space and throwing a General Protection Fault.

      Two seconds later, while stepping into a secondary rescue routine to drop conflicting operations, it reads a dead memory address structure inside rb_first(), throwing a critical Kernel Paging Oops that completely crashes the host operating system context.

      2026-07-04T23:16:03-07:00 general protection fault: 0000 [#1] SMP NOPTI
      2026-07-04T23:16:03-07:00 CPU: 3 PID: 3722867 Comm: drbd_w_pvc-385f Tainted: G           O      4.19.0+1 #1
      2026-07-04T23:16:03-07:00 Hardware name:  /S8056GME-HOV-B, BIOS V1.25 (0x80) 01/17/2025
      2026-07-04T23:16:03-07:00 RIP: e030:drbd_bm_count_bits+0x223/0x300 [drbd]
      2026-07-04T23:16:03-07:00 Code: 24 08 01 49 39 ee 4c 8b 4c 24 18 44 8b 54 24 20 0f 83 5c ff ff ff 44 89 fb e9 69 fe ff ff 89 d8 44 01 d3 48 83 c5 20 c1 e8 05 <8b> 3c 86 f3 0f b8 c7 90 89 c7 49 01 ff 81 fb ff 7f 00 00 77 a3 48
      2026-07-04T23:16:03-07:00 RSP: e02b:ffffc90047dcfcb8 EFLAGS: 00010016
      2026-07-04T23:16:05-07:00 BUG: unable to handle kernel paging request at ffffc90047dcfdc0
      2026-07-04T23:16:05-07:00 PGD 1f69c6067 P4D 1f69c6067 PUD 265d1f067 PMD 1a26fe067 PTE 0
      2026-07-04T23:16:05-07:00 Oops: 0000 [#2] SMP NOPTI
      2026-07-04T23:16:05-07:00 CPU: 3 PID: 3722891 Comm: drbd_r_pvc-385f Tainted: G      D    O      4.19.0+1 #1
      2026-07-04T23:16:05-07:00 RIP: e030:rb_first+0xd/0x20
      2026-07-04T23:16:05-07:00 CR2: ffffc90047dcfdc0 CR3: 000000024fbb6000 CR4: 0000000000040660
      2026-07-04T23:16:05-07:00 Call Trace:
      2026-07-04T23:16:05-07:00  drbd_cancel_conflicting_resync_requests+0x38/0x2d0 [drbd]
      2026-07-04T23:16:05-07:00  ? conn_disconnect+0x19c/0xce0 [drbd]
      2026-07-04T23:16:05-07:00  ? drbd_receiver+0x361/0x9a0 [drbd]
      2026-07-04T23:16:05-07:00  ? drbd_thread_setup+0xd0/0x230 [drbd]
      
      

      Stage 4: Cascading Failures & Pool Master Dropout

      Timestamp: 23:16:05 - 23:21:50 PDT

      As xen04 drops dead instantly, surviving nodes encounter abrupt link terminations (BrokenPipe). The core etcd consensus cluster node on master01 encounters an extensive 2.92-second serialization freeze while attempting to log state, following a complete loss of response from the crashed host. At 23:21:50, the Pool Master node xen01 officially declares xen04 dead after exhausting its network PingAck heartbeat retry limits.

      2026-07-04T23:16:05-07:00 {"time":"2026-07-05T02:16:05.872109Z","stream":"stderr","message":"{\"level\":\"warn\",\"ts\":\"2026-07-05T06:16:05.872109Z\",\"caller\":\"txn/util.go:93\",\"msg\":\"apply request took too long\",\"took\":\"2.926882374s\",\"expected-duration\":\"100ms\",\"prefix\":\"read-only range \",\"request\":\"key:\\\"/registry/persistentvolumes/pvc-385f674a-3dcd-4cfb-8f4d-e4a7157becd1\\\" limit:1 \"}"}
      2026-07-04T23:16:17-07:00 drbd pvc-7bffac62-0d6d-4fe4-a784-c71fe007ac88 ovbh-pprod-xen03: conn( Connected -> BrokenPipe ) peer( Secondary -> Unknown )
      2026-07-04T23:21:50-07:00 drbd xcp-volume-3232b7e9-10d4-45ec-84ca-ad598bf428c6 ovbh-pprod-xen04: conn( Connected -> NetworkFailure ) peer( Primary -> Unknown )
      2026-07-04T23:21:50-07:00 drbd xcp-volume-3232b7e9-10d4-45ec-84ca-ad598bf428c6 ovbh-pprod-xen04: PingAck did not arrive in time.
      

      Full velero details

      jonathon@jonathon-framework:~$ velero --kubeconfig k8s_configs/production.yaml describe backup openvas-daily-20260705061500 --details
      Name:         openvas-daily-20260705061500
      Namespace:    velero
      Labels:       app.kubernetes.io/name=openvas
                    velero.io/schedule-name=openvas-daily
                    velero.io/storage-location=default
      Annotations:  objectset.rio.cattle.io/applied=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
                    objectset.rio.cattle.io/id=5f8afe4b-1b5f-4e00-906b-21745abf859f
                    velero.io/resource-timeout=10m0s
                    velero.io/source-cluster-k8s-gitversion=v1.35.4+rke2r1
                    velero.io/source-cluster-k8s-major-version=1
                    velero.io/source-cluster-k8s-minor-version=35
      
      Phase:  Completed
      
      
      Namespaces:
        Included:  openvas
        Excluded:  <none>
      
      Resources:
        Included cluster-scoped:    <none>
        Excluded cluster-scoped:    volumesnapshotcontents.snapshot.storage.k8s.io
        Included namespace-scoped:  *
        Excluded namespace-scoped:  volumesnapshots.snapshot.storage.k8s.io
      
      Label selector:  <none>
      
      Or label selector:  <none>
      
      Storage Location:  default
      
      Velero-Native Snapshot PVs:  true
      Snapshot Move Data:          true
      Data Mover:                  velero
      
      TTL:  720h0m0s
      
      CSISnapshotTimeout:    30m0s
      ItemOperationTimeout:  4h0m0s
      
      Hooks:  <none>
      
      Backup Format Version:  1.1.0
      
      Started:    2026-07-04 23:15:00 -0700 PDT
      Completed:  2026-07-04 23:17:33 -0700 PDT
      
      Expiration:  2026-08-03 23:15:00 -0700 PDT
      
      Total items to be backed up:  42
      Items backed up:              42
      
      Backup Item Operations:
        Operation for persistentvolumeclaims openvas/gvmd-pvc:
          Backup Item Action Plugin:  velero.io/csi-pvc-backupper
          Operation ID:               du-4d7f65aa-ec24-421d-8b30-9ab70a10172b.a1974f4d-2923-403c839c5
          Items to Update:
                                 datauploads.velero.io velero/openvas-daily-20260705061500-v86h2
          Phase:                 Completed
          Progress:              8896914780 of 8896914780 complete (Bytes)
          Progress description:  Completed
          Created:               2026-07-04 23:15:08 -0700 PDT
          Started:               2026-07-04 23:15:30 -0700 PDT
          Updated:               2026-07-04 23:17:11 -0700 PDT
        Operation for persistentvolumeclaims openvas/openvas-pvc:
          Backup Item Action Plugin:  velero.io/csi-pvc-backupper
          Operation ID:               du-4d7f65aa-ec24-421d-8b30-9ab70a10172b.105299a3-d117-45630a803
          Items to Update:
                                 datauploads.velero.io velero/openvas-daily-20260705061500-92dtr
          Phase:                 Completed
          Progress:              5540 of 5540 complete (Bytes)
          Progress description:  Completed
          Created:               2026-07-04 23:15:13 -0700 PDT
          Started:               2026-07-04 23:15:38 -0700 PDT
          Updated:               2026-07-04 23:16:54 -0700 PDT
        Operation for persistentvolumeclaims openvas/psql-pvc:
          Backup Item Action Plugin:  velero.io/csi-pvc-backupper
          Operation ID:               du-4d7f65aa-ec24-421d-8b30-9ab70a10172b.23fb6277-0f6f-4836bb7b8
          Items to Update:
                                 datauploads.velero.io velero/openvas-daily-20260705061500-jp7gd
          Phase:                 Completed
          Progress:              24267413354 of 24267413354 complete (Bytes)
          Progress description:  Completed
          Created:               2026-07-04 23:15:18 -0700 PDT
          Started:               2026-07-04 23:15:42 -0700 PDT
          Updated:               2026-07-04 23:17:15 -0700 PDT
      Resource List:
        apiextensions.k8s.io/v1/CustomResourceDefinition:
          - certificaterequests.cert-manager.io
          - certificates.cert-manager.io
          - clusterserviceversions.operators.coreos.com
        apps/v1/Deployment:
          - openvas/openvas
          - openvas/test
        apps/v1/ReplicaSet:
          - openvas/openvas-64786df449
          - openvas/openvas-69bb998d7c
          - openvas/openvas-6db7bcd6ff
          - openvas/openvas-6dd46f4f79
          - openvas/openvas-6f8d45b667
          - openvas/openvas-78dc6f74c6
          - openvas/openvas-7c5654b9d6
          - openvas/openvas-844c5f796d
          - openvas/openvas-86d9b75d9f
          - openvas/openvas-b97749f55
          - openvas/openvas-d9d48c74
          - openvas/test-5879777846
          - openvas/test-5bd7f76f8c
          - openvas/test-6487578786
          - openvas/test-6b467857f5
        cert-manager.io/v1/Certificate:
          - openvas/openvas-ingress-cert-fp-pki
        cert-manager.io/v1/CertificateRequest:
          - openvas/openvas-ingress-cert-fp-pki-15
        discovery.k8s.io/v1/EndpointSlice:
          - openvas/openvas-service-6zghf
        networking.k8s.io/v1/Ingress:
          - openvas/openvas
        operators.coreos.com/v1alpha1/ClusterServiceVersion:
          - openvas/node-healthcheck-operator.v0.11.0
          - openvas/self-node-remediation.v0.12.1
        v1/ConfigMap:
          - openvas/elasticsearch-es-transport-ca-internal
          - openvas/init-scripts-config
          - openvas/kube-root-ca.crt
        v1/Endpoints:
          - openvas/openvas-service
        v1/Namespace:
          - openvas
        v1/PersistentVolume:
          - pvc-105299a3-d117-4562-a2e7-8b6be53cfde0
          - pvc-23fb6277-0f6f-483c-a245-3198dbeff0b2
          - pvc-a1974f4d-2923-4036-8187-43ed0d26e1c4
        v1/PersistentVolumeClaim:
          - openvas/gvmd-pvc
          - openvas/openvas-pvc
          - openvas/psql-pvc
        v1/Pod:
          - openvas/openvas-78dc6f74c6-wcwp2
        v1/Secret:
          - openvas/gvmd-secrets
          - openvas/openvas-ingress-tls-fp-pki
        v1/Service:
          - openvas/openvas-service
        v1/ServiceAccount:
          - openvas/default
      
      Backup Volumes:
        Velero-Native Snapshots: <none included>
      
        CSI Snapshots:
          openvas/gvmd-pvc:
            Data Movement:
              Operation ID: du-4d7f65aa-ec24-421d-8b30-9ab70a10172b.a1974f4d-2923-403c839c5
              Data Mover: velero
              Uploader Type: kopia
              Moved data Size (bytes): 8896914780
          openvas/openvas-pvc:
            Data Movement:
              Operation ID: du-4d7f65aa-ec24-421d-8b30-9ab70a10172b.105299a3-d117-45630a803
              Data Mover: velero
              Uploader Type: kopia
              Moved data Size (bytes): 5540
          openvas/psql-pvc:
            Data Movement:
              Operation ID: du-4d7f65aa-ec24-421d-8b30-9ab70a10172b.23fb6277-0f6f-4836bb7b8
              Data Mover: velero
              Uploader Type: kopia
              Moved data Size (bytes): 24267413354
      
        Pod Volume Backups: <none included>
      
      HooksAttempted:  0
      HooksFailed:     0
      

      f9797a22-d4cf-40ae-8da5-6a7d580ef137-image.jpeg

      linstor-pvc-velero-logs.txt
      xen04-07042026-panic.txt
      linstor-controller-logs.txt

      poddingueP 1 Reply Last reply Reply Quote 0
      • poddingueP Offline
        poddingue Vates 🪐 @Jonathon
        last edited by

        The timing evidence here looks strong to me. Your second Grafana window is doing a lot of work: linstor-satellite.service jumps to roughly 8,700 log lines in the three minutes around the panic, well above linstor-controller at 926 and xapi at 460, and the priority chart goes red at the same moment. A backup that fans out volume creates and deletes across three replicas, landing on a DRBD race, fits what you are seeing.

        Throttling Velero should tell you a lot. If the crashes stop with clientQPS: 3 and itemBlockWorkerCount: 1, that narrows it to concurrency rather than anything about those particular volumes.

        For the logs question, a xen-bugtool --yestoall bundle from a host that has panicked is usually the thing people ask for first (https://docs.xcp-ng.org/troubleshooting/log-files), since it sweeps up the kernel side alongside the storage logs you already have in Loki. I don't know DRBD internals well enough to say which trace matters most, so it might be worth a mention to @Team-Storage. They can say what they actually need rather than have you guess, and a panic that reproduces on a schedule is a good deal easier for them to chase than most.

        J 1 Reply Last reply Reply Quote 0
        • J Offline
          Jonathon @poddingue
          last edited by

          @poddingue

          I should already have all the logs, including kernel2ce97f35-954d-4f1b-88a5-ae0899e75d99-image.jpeg

          Nothing has happened since. I am also increasing dom0 ram for all hosts.

          poddingueP 1 Reply Last reply Reply Quote 0
          • poddingueP Offline
            poddingue Vates 🪐 @Jonathon
            last edited by poddingue

            That it's stayed quiet since you throttled Velero is a good sign, and it lines up with the concurrency theory rather than anything about the specific volumes. 🤔
            Bumping dom0 RAM makes sense too, since linstor-satellite spiking to roughly 926 log lines around the panic suggests dom0 was under real pressure right then. 👍
            If it does come back, a xen-bugtool --yestoall bundle from the host that panicked, plus the Loki window you already have, would give @Team-Storage something concrete to line up against the DRBD side.
            I'm not sure whether the real fix sits in Velero's pacing or in how LINSTOR handles concurrent create/delete, but the reproduction you've narrowed down is genuinely useful.
            Fingers crossed it stays boring from here. 🤞

            J 1 Reply Last reply Reply Quote 0
            • J Offline
              Jonathon @poddingue
              last edited by

              @poddingue Just had a new crash. Got the export bug-report-20260719233946.tar.bz2 it is ~63MB There is a way to share large files but it has been a bit since I have done that so have forgotten.
              I've got all the logs. Will dig into it in the morning. Also looking into ways to share grafana links securely. We have it behind Cloudflare Zero Trust.
              d16f2a36-3e18-4237-b134-99c29650cd72-image.jpeg
              Here you can see when the host was offline.
              22c5da35-ac6e-4ed4-94ab-1a87fbd1def5-image.jpeg

              poddingueP 1 Reply Last reply Reply Quote 0
              • poddingueP Offline
                poddingue Vates 🪐 @Jonathon
                last edited by

                On the bundle, the docs warn it can carry sensitive details about your setup, so better not to attach it publicly: https://docs.xcp-ng.org/troubleshooting/log-files#produce-a-status-report. As far as I can tell there is no self-serve upload spot, it is usually someone from Vates dropping you a private Nextcloud link when you ask, so flagging here that you have the bundle ready is probably the quickest route.

                Since this was a kernel panic, is there anything in /var/crash on the host that went down, and which host was it this time? The earlier ones were xen04 and xen03.

                J 1 Reply Last reply Reply Quote 0
                • J Offline
                  Jonathon @poddingue
                  last edited by Jonathon

                  @poddingue This time it was host xen05. I got the request link for upload, so I have uploaded the bundle as well as all logs from xen05 and xen01 (xcp-ng pool master and had linstor-controller) So hoping we have everything needed. I will be digging into it to. It is in json format with all labels. Nothing in /var/crash/

                  J 1 Reply Last reply Reply Quote 0
                  • J Offline
                    Jonathon @Jonathon
                    last edited by

                    Looks to be similar to last time

                    Time,Node,Component / Service,Logged Event & Impact
                    23:17:13,xen01,LINSTOR/Controller,Resource Created: linstor-csi provisions a short-lived volume: pvc-395da199-d455-4004-ac0d-f6c6016ebf4e.
                    23:17:16,xen01,kernel (drbd),Sync Begins: xen01 connects to xen05 as a SyncSource and begins synchronizing the volume to it.
                    23:17:49,xen01,LINSTOR/Controller,Teardown Requested: The CSI plugin changes its mind or finishes its task, requesting sequential deletion (DelRsc) of the volume replicas across the cluster.
                    23:17:51,xen01,LINSTOR/Controller,Source Disk Removed: Linstor removes the volume from xen01 itself (Toggle Disk ... removing disk).
                    23:17:52,xen01,kernel (drbd),Source Goes Diskless: xen01 detaches the underlying storage block (UpToDate -> Detaching -> Diskless). It alerts peers it can no longer satisfy read requests, calling drbd_bm_resize with capacity == 0.
                    23:17:53,xen05,LINSTOR/Satellite, While the cluster connection is actively tearing down, xen05's local background DeviceManager wakes up and detects the volume. It attempts an online re-alignment to round up the block layer size to match the 4MiB extent rule (26220040 KiB to 26222592 KiB).
                    23:17:54,xen05,kernel (drbd),Fatal Crash: xen05's DRBD driver tries to resize and count its synchronization bitmap block pointers. Because its peer source (xen01) dropped to zero capacity mid-flight, DRBD hits memory corruption. It triggers a General Protection Fault at drbd_bm_count_bits+0x223/0x300 and panics the kernel.
                    
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                    • J Offline
                      Jonathon @Jonathon
                      last edited by Jonathon

                      My first idea was to have velero use a different storage class. Something like

                      apiVersion: storage.k8s.io/v1
                      kind: StorageClass
                      metadata:
                        name: linstor-ephemeral-retain
                      parameters:
                        linstor.csi.linbit.com/allowRemoteVolumeAccess: "true"
                        linstor.csi.linbit.com/disklessOnRemaining: "true"
                        linstor.csi.linbit.com/disklessStoragePool: DfltDisklessStorPool
                        linstor.csi.linbit.com/placementCount: "3"
                      provisioner: linstor.csi.linbit.com
                      **reclaimPolicy: Retain**
                      volumeBindingMode: WaitForFirstConsumer
                      

                      Then have a cronjob collected the Released pvcs every hour. The problem is that can not work, as velero uses the storage class of the backed up pvc. So I would have to change every linstor storage class to Retain, and would effectively disable the automatic garbage collection for the cluster. Which might be fine, but would love to avoid it.

                      My second idea is to eliminate the need for the resizing (another work around to hopefully get away from this race condition/bug)
                      I am also not seeing any way to modify the storageclass to round up or pad the pv. This would be to attempt to eliminate the need for drbd_bm_resize.
                      Currently looking into Kyverno Mutating Webhook to dynamically pad these volumes on the fly to see if that would help me out at all.
                      All pvs are already whole numbers of Gi.
                      Velero calculates the size of the temporary clone pvc based on the exact byte-count of the used/allocated snapshot metadata, not the #Gi specification of the original pvc.
                      Just confirmed with a test
                      594a3691-1055-4aa3-a3f4-b35e731390d4-image.jpeg

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                      • J Offline
                        Jonathon @Jonathon
                        last edited by

                        I was just moving around the velero backup schedules when it decided to run some again even though it was not time. Crashed xen04 this time. Deleting the possible offending backup schedule until this bug can be identified and fixed.

                        Uploaded new bug bundle to nextcloud too.

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                        • J Offline
                          Jonathon @Jonathon
                          last edited by Jonathon

                          Logs from xen04 look like they are the same too. Which makes sense.

                          20:01:53.805: The Linstor DeviceManager on xen04 triggered an asynchronous alignment for a newly created volume (pvc-fac0a18b-2c23-4fe8-b005-b4f492cec92f), padding it from 26220040 KiB to 26222592 KiB.
                          
                          20:01:54.034: Simultaneously, an orchestrator (like Velero) began tearing the volume down, shifting the DRBD state to conn( Connected -> TearDown ) and pdsk( Diskless -> DUnknown ).
                          
                          20:01:58.484: The DRBD worker thread evaluated the shrinking bitmap while the alignment was trying to alter it. This caused the general protection fault: 0000 [#1] SMP NOPTI at instruction RIP: e030:drbd_bm_count_bits+0x223/0x300 [drbd], crashing the kernel.
                          
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                          • poddingueP Offline
                            poddingue Vates 🪐 @Jonathon
                            last edited by

                            That timeline is the clearest version of this yet. xen04 going down the same way as xen05 makes the race look real to me rather than coincidental, unless I am reading the ordering wrong.
                            The fault lands inside drbd_bm_count_bits, so in the DRBD module itself, which makes me think this is an upstream LINBIT question as much as an XCP-ng one. I do not know enough about how that module gets packaged here to say who owns the fix though. Might be worth another mention to @Team-Storage so someone can open your bundles with your post #10 next to them.
                            On the padding idea I am out of my depth: no idea whether LINSTOR can be told to pre-round a volume at creation, but asking LINBIT directly seems worth a try since it would sidestep drbd_bm_resize entirely. 🤷

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                            • M Offline
                              MajorP93 @poddingue
                              last edited by MajorP93

                              @jonathon are you using your LINSTOR/DRBD stack in the form of licensed XOSTOR? Your issue looks a case for pro support. Did you consider opening a case with pro support?

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                              • J Offline
                                Jonathon @MajorP93
                                last edited by Jonathon

                                @MajorP93 No we do not have pro support at the moment

                                hmmm. Really seems like a build with 9.2.19 could fix all of this.
                                How can I request for a build @poddingue ?

                                https://github.com/LINBIT/drbd/blob/drbd-9.2.19/ChangeLog#L61
                                9.2.17

                                • Fix a kernel crash triggered by a crafted/invalid netlink message

                                https://github.com/LINBIT/drbd/blob/drbd-9.2.19/ChangeLog#L24
                                9.2.19

                                • Fix an AB-BA deadlock between online resize and activity-log transactions
                                • Fix several races during connection teardown that could crash or
                                  hang (ack_sender requeue, pending ping work, in-progress lb-tcp
                                  connect)
                                poddingueP 1 Reply Last reply Reply Quote 0
                                • poddingueP Offline
                                  poddingue Vates 🪐 @Jonathon
                                  last edited by

                                  On the version question, 8.3 ships DRBD 9.2.18 right now (that's what kmod-drbd.spec says on the 8.3 branch), so you'd be asking for a single point bump rather than a big jump.
                                  That probably helps you. Of your two links though, I think the netlink crash fix is a 9.2.17 entry, which would mean it's already in what you're running. 🤷
                                  The 9.2.19 line that looks closest to your crash to me is the connection-teardown races one rather than the AB-BA deadlock, since a deadlock would hang rather than throw a GPF, but you've read these traces far more closely than I have so correct me if that's backwards.
                                  I can't request a build myself, that's a @Team-Storage call rather than mine, though your post #13 timeline next to those changelog lines is a stronger case than most version-bump requests turn up with.

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                                  • J Offline
                                    Jonathon @poddingue
                                    last edited by Jonathon

                                    @poddingue I'm fully up to date, but only at version 9.2.16

                                    [14:57 ovbh-pprod-xen02 ~]# drbdadm --version
                                    DRBDADM_BUILDTAG=GIT-hash:\ 71c8bcff6ea77a022b272a7eba649a774251bac4\ build\ by\ @buildsystem\,\ 2025-11-03\ 10:21:36
                                    DRBDADM_API_VERSION=2
                                    DRBD_KERNEL_VERSION_CODE=0x090210
                                    DRBD_KERNEL_VERSION=9.2.16
                                    DRBDADM_VERSION_CODE=0x092100
                                    DRBDADM_VERSION=9.33.0
                                    [14:57 ovbh-pprod-xen02 ~]# drbd-reactor --version
                                    drbd-reactor 1.9.0
                                    [14:57 ovbh-pprod-xen02 ~]# 
                                    

                                    ae60a96f-99c9-4e31-9f74-362d7d4426d7-image.jpeg

                                    There are no updates that I can install

                                    [14:08 ovbh-pprod-xen02 ~]# yum check-update
                                    Loaded plugins: fastestmirror
                                    Loading mirror speeds from cached hostfile
                                    Excluding mirror: updates.xcp-ng.org
                                     * xcp-ng-base: mirrors.xcp-ng.org
                                    Excluding mirror: updates.xcp-ng.org
                                     * xcp-ng-updates: mirrors.xcp-ng.org
                                    zabbix                                                                                                                                                                                                                                 | 3.0 kB  00:00:00     
                                    zabbix-non-supported                                                                                                                                                                                                                   | 2.9 kB  00:00:00     
                                    zabbix/x86_64/primary_db                                                                                                                                                                                                               | 114 kB  00:00:00     
                                    
                                    zabbix-agent.x86_64                                                                                                         7.0.28-release1.el7                                                                                                         zabbix
                                    
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                                    • J Offline
                                      Jonathon @Jonathon
                                      last edited by

                                      For now I have upgraded all hosts to use --enablerepo=xcp-ng-linstor-testing to get kmod-drbd.x86_64 0:9.2.18-2.0.xcpng8.3
                                      That way it is there to be picked up if the host crashes again.
                                      https://github.com/xcp-ng-rpms/drbd/blob/master/SPECS/kmod-drbd.spec
                                      https://koji.xcp-ng.org/buildinfo?buildID=5747

                                      [12:15 ovbh-pprod-xen04 ~]# yum upgrade --enablerepo=xcp-ng-linstor-testing
                                      Loaded plugins: fastestmirror
                                      Loading mirror speeds from cached hostfile
                                      Excluding mirror: updates.xcp-ng.org
                                       * xcp-ng-base: mirrors.xcp-ng.org
                                      Excluding mirror: updates.xcp-ng.org
                                       * xcp-ng-updates: mirrors.xcp-ng.org
                                      grafana/signature                                                                                                                                                                                                                      |  810 B  00:00:00     
                                      grafana/signature                                                                                                                                                                                                                      | 3.0 kB  00:00:00 !!! 
                                      xcp-ng-linstor-testing/signature                                                                                                                                                                                                       |  473 B  00:00:00     
                                      xcp-ng-linstor-testing/signature                                                                                                                                                                                                       | 3.0 kB  00:00:00 !!! 
                                      zabbix                                                                                                                                                                                                                                 | 3.0 kB  00:00:00     
                                      zabbix-non-supported                                                                                                                                                                                                                   | 2.9 kB  00:00:00     
                                      (1/3): grafana/primary_db                                                                                                                                                                                                              | 879 kB  00:00:00     
                                      (2/3): xcp-ng-linstor-testing/primary_db                                                                                                                                                                                               | 2.4 kB  00:00:00     
                                      (3/3): zabbix/x86_64/primary_db                                                                                                                                                                                                        | 114 kB  00:00:00     
                                      Resolving Dependencies
                                      --> Running transaction check
                                      ---> Package kmod-drbd.x86_64 0:9.2.16-1.0.xcpng8.3 will be updated
                                      ---> Package kmod-drbd.x86_64 0:9.2.18-2.0.xcpng8.3 will be an update
                                      ---> Package zabbix-agent.x86_64 0:7.0.27-release1.el7 will be updated
                                      ---> Package zabbix-agent.x86_64 0:7.0.28-release1.el7 will be an update
                                      --> Finished Dependency Resolution
                                      
                                      Dependencies Resolved
                                      
                                      ==============================================================================================================================================================================================================================================================
                                       Package                                                    Arch                                                 Version                                                           Repository                                                            Size
                                      ==============================================================================================================================================================================================================================================================
                                      Updating:
                                       kmod-drbd                                                  x86_64                                               9.2.18-2.0.xcpng8.3                                               xcp-ng-linstor-testing                                               2.8 M
                                       zabbix-agent                                               x86_64                                               7.0.28-release1.el7                                               zabbix                                                               660 k
                                      
                                      Transaction Summary
                                      ==============================================================================================================================================================================================================================================================
                                      Upgrade  2 Packages
                                      
                                      Total download size: 3.4 M
                                      Is this ok [y/d/N]: y
                                      Downloading packages:
                                      Delta RPMs disabled because /usr/bin/applydeltarpm not installed.
                                      (1/2): zabbix-agent-7.0.28-release1.el7.x86_64.rpm                                                                                                                                                                                     | 660 kB  00:00:00     
                                      (2/2): kmod-drbd-9.2.18-2.0.xcpng8.3.x86_64.rpm                                                                                                                                                                                        | 2.8 MB  00:00:01     
                                      --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                      Total                                                                                                                                                                                                                         2.8 MB/s | 3.4 MB  00:00:01     
                                      Running transaction check
                                      Running transaction test
                                      Transaction test succeeded
                                      Running transaction
                                        Updating   : kmod-drbd-9.2.18-2.0.xcpng8.3.x86_64                                                                                                                                                                                                       1/4 
                                        Updating   : zabbix-agent-7.0.28-release1.el7.x86_64                                                                                                                                                                                                    2/4 
                                        Cleanup    : kmod-drbd-9.2.16-1.0.xcpng8.3.x86_64                                                                                                                                                                                                       3/4 
                                        Cleanup    : zabbix-agent-7.0.27-release1.el7.x86_64                                                                                                                                                                                                    4/4 
                                        Verifying  : zabbix-agent-7.0.28-release1.el7.x86_64                                                                                                                                                                                                    1/4 
                                        Verifying  : kmod-drbd-9.2.18-2.0.xcpng8.3.x86_64                                                                                                                                                                                                       2/4 
                                        Verifying  : kmod-drbd-9.2.16-1.0.xcpng8.3.x86_64                                                                                                                                                                                                       3/4 
                                        Verifying  : zabbix-agent-7.0.27-release1.el7.x86_64                                                                                                                                                                                                    4/4 
                                      
                                      Updated:
                                        kmod-drbd.x86_64 0:9.2.18-2.0.xcpng8.3                                                                                       zabbix-agent.x86_64 0:7.0.28-release1.el7                                                                                      
                                      
                                      Complete!
                                      
                                      poddingueP 1 Reply Last reply Reply Quote 0
                                      • poddingueP Offline
                                        poddingue Vates 🪐 @Jonathon
                                        last edited by poddingue

                                        Oopsie, I was wrong.
                                        I owe you a correction on the version, and that one is on me. I said 8.3 ships 9.2.18, but I was reading the spec file on the branch rather than what you actually get from the stable repo. 🤷
                                        Your yum check-update output answers it better than I did: stable leaves you on 9.2.16, and 9.2.18 only turns up once xcp-ng-linstor-testing is enabled.

                                        The screenshot in that same post is the part the still puzzles me. XO says "All good, patches up to date" while the module underneath is two point releases back, which I assume is what everyone else running XOSTOR sees too. If the connection-teardown fixes you found really are in 9.2.19, that is three releases of distance on the exact code path your traces land in, not the single bump I described.

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                                        • M Offline
                                          Mathieu L Vates 🪐 XCP-ng Team
                                          last edited by

                                          Hello,

                                          Indeed this is a known issue with XOSTOR, when causing a sync of too many resources at once it's possible for a DRBD resource to leak memory during the resync. A patch on the 9.2.18 fixes this by throttling the number of resources that can be synced at once to mitigate the issue.

                                          The 9.2.18 update should be in the main xcp-ng-linstor repo very soon.

                                          What you can do too is give more RAM to the dom0 of your hosts. How many RAM have been allocated to dom0 at the moment? We advise 16GB or 32GB depending on the number of volumes.

                                          J 1 Reply Last reply Reply Quote 1
                                          • J Offline
                                            Jonathon @Mathieu L
                                            last edited by

                                            @Mathieu-L https://xcp-ng.org/forum/post/106873 I had increased it to 16G and it still crashed.

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