Okay, this is a complex situation with several interwoven issues. Let's break down what we can glean from the information and then outline potential solutions.
**1. Summary of the Situation**
* **Ghost VMs/Failed Migration:** You're dealing with two VMs that were apparently migrated between nodes in your Proxmox cluster. These VMs, after the migration, are exhibiting errors (indicated by "failed migration" and related errors).
* **Node Behavior:** The issues seem to be concentrated on the primary node ("tiber"). The two failing VMs ended up on node "marcus". The success story happened on the same node as the second migration success.
* **Proxmox Cluster:** You have a Proxmox cluster with at least three nodes ("tiber", "marcus").
* **Software Versions:** All nodes are running Proxmox 8.4.0 with kernel 6.8.12-9. This means your environment is fairly consistent in terms of underlying software.
* **Storage:** The storage configuration isn't detailed, but it's likely that the VMs use a shared storage solution (e.g., Ceph, NFS, iSCSI) since they could be moved between nodes.
**2. Potential Causes and Troubleshooting Steps**
Let's organize these into categories: Cluster, Storage, and Configuration/VM Specific.
**A. Cluster-Level Issues (Most Likely)**
* **ZFS Corruption (Critical):** ZFS is notorious for silently corrupting data under certain conditions (memory errors, hardware failures, power fluctuations). Given the inconsistent behavior, ZFS corruption is *the* most concerning possibility.
* **Immediate Action:** Run `zpool scrub` on *all* ZFS pools used by your cluster. This process checks the data integrity and attempts to repair errors. *Do not interrupt a scrub.* A full scrub can take a *long* time.
* **Monitoring:** Set up ZFS pool health monitoring alerts.
* **Hardware:** If you find errors during scrubbing, investigate your hardware (RAM, disks, controllers). Bad hardware can cause ZFS corruption.
* **Corosync/Pacemaker Instability:** Issues with the cluster's heartbeat and failover mechanisms can lead to migration failures.
* **Check Logs:** Examine the Corosync and Pacemaker logs (`/var/log/corosync/corosync.log`, `/var/log/pacemaker/pacemaker.log`). Look for errors or warnings related to heartbeat failures, quorum issues, or resource conflicts.
* **Restart Services:** As a test (and only if you understand the implications), try restarting the Corosync and Pacemaker services on *all* nodes: `systemctl restart corosync pacemaker`
* **Network Issues:** Network instability during the migration can corrupt data.
* **Check Network Connectivity:** Ensure all nodes can reliably communicate with each other over the network. Use `ping` and `traceroute` to check for latency and packet loss.
* **MTU:** Ensure consistent MTU settings across all nodes and network devices.
**B. Storage-Level Issues**
* **Storage Connectivity Problems:** If using shared storage (Ceph, NFS, iSCSI), verify that all nodes have stable and reliable access to the storage.
* **Storage Controller Issues:** Problems with the storage controller (RAID controller, HBA) can cause data corruption during migration. Check the controller logs and firmware.
* **NFS Permissions (If applicable):** If using NFS, double-check that the Proxmox user (usually `root`) has the necessary permissions to read and write to the NFS shares.
**C. Configuration/VM-Specific Issues**
* **VM Disk Format:** Are the VMs using QCOW2 or raw disks? QCOW2 has copy-on-write features that might be interacting with the migration process in unexpected ways. While less likely, consider testing with a different disk format if you can.
* **VM Configuration Errors:** Review the VM configurations, especially related to storage and networking. Look for inconsistencies or errors.
* **Guest OS Issues:** While less likely, it's possible that the guest operating systems themselves have issues that are being exposed during the migration. (Though, you've stated success with other migrations).
**3. Immediate Steps to Take**
1. **Prioritize ZFS Scrub:** **Immediately** run `zpool scrub` on all ZFS pools. This is the highest priority.
2. **Backup (if possible):** If you can, attempt to back up the affected VMs before making any further changes. Even a partial backup is better than nothing.
3. **Isolate the Affected VMs:** Stop the affected VMs to prevent further data corruption.
4. **Check Logs:** Thoroughly review the Proxmox logs on *all* nodes, especially the logs around the time of the migration failures. The logs are your best source of information. Look at system logs (`/var/log/syslog`), Proxmox logs (`/var/log/pve/`), and ZFS logs if available.
5. **Reduce Cluster Load:** If possible, reduce the overall load on the cluster to minimize the risk of further errors.
**4. Investigation and Long-Term Solutions**
* **Hardware Diagnostics:** Run comprehensive hardware diagnostics, including memory tests, disk SMART tests, and controller tests.
* **ZFS Monitoring:** Implement ZFS monitoring tools to detect and alert you to potential problems.
* **Network Monitoring:** Monitor network performance to identify any issues that could be affecting migration reliability.
* **Proxmox Updates:** Ensure that your Proxmox cluster is running the latest stable version.
**Important Considerations**
* **Data Integrity is Paramount:** Do not prioritize fixing the migration issue at the expense of data integrity. If you suspect data corruption, focus on restoring from backups.
* **Document Everything:** Carefully document all of your troubleshooting steps and findings. This will help you identify patterns and track your progress.
* **Seek Expert Help:** If you're not comfortable troubleshooting this issue yourself, seek help from a Proxmox expert or consultant.
To help me provide more specific advice, could you tell me:
* **What type of storage are you using?** (Ceph, NFS, iSCSI, ZFS local, etc.)
* **How large are the affected VMs?**
* **What operating systems are running inside the VMs?**
* **Can you share a snippet of the Proxmox logs related to the migration failures?** (Redact any sensitive information)
