Learn how to resolve KVM internal error. Suberror 1 quickly. Our KVM Support team is here to help you with your questions and concerns.

Troubleshooting “KVM Internal Error: Suberror 1” in Virtualization

Have you been having trouble with the error message “KVM internal error. Suberror 1” while working with Kernel-based Virtual Machine?

According to our Experts, this error usually occurs when dealing with an issue deep within the virtualization stack. This error can be complex, but with the right guide we can take the right steps to troubleshoot and restore functionality to
our virtual machines (VMs).

An Overview:

1. What is KVM?
2. What is “KVM Internal Error: Suberror 1”?
3. Potential Causes of “KVM Internal Error: Suberror 1”
4. Troubleshooting Steps
5. Example Commands for Diagnosis
6. Advanced Troubleshooting Techniques
7. Performance Optimization Tips

What is KVM?

KVM (Kernel-based Virtual Machine) is a Linux kernel module that enables the kernel to function as a hypervisor, allowing multiple VMs to run on a single physical host. KVM leverages hardware virtualization features, such as Intel VT-x or AMD-V, to efficiently manage virtual environments.

What is “KVM Internal Error: Suberror 1”?

The “KVM internal error. Suberror 1” lets us know that there’s an internal problem within the KVM virtualization layer. This error can pop up due to several reasons, often involving the interaction between the host system and the VM.

Potential Causes of “KVM Internal Error: Suberror 1”

1. Incorrect or conflicting settings in the VM or KVM configuration can lead to internal errors. Misconfigured CPU, memory, or hardware parameters are common culprits.
2. If the host system is running low on resources like CPU or memory, or if there’s contention between multiple VMs, KVM may generate internal errors.
3. Bugs in the Linux kernel or the KVM module itself can cause unexpected errors. This is more likely if we are using a kernel version with known issues or a buggy version of KVM.
4. Problems with the host hardware, such as faulty CPU virtualization extensions (VT-x/AMD-V), can result in KVM internal errors. Incorrect BIOS/UEFI settings can also impact virtualization.
5. Discrepancies between the host kernel version, KVM version, and the VM’s configuration can lead to errors. It’s essential to ensure all components are compatible and up-to-date.
6. If the virtual machine disk file or image is corrupted, KVM may fail when trying to interact with the VM.

Troubleshooting Steps

We can easily resolve the “KVM internal error. Suberror 1” with these steps:

• First, examine the KVM and system logs for more specific error messages:
• VM-specific logs: Located in `/var/log/libvirt/qemu/`.
• System-wide messages: Check `/var/log/messages` or `/var/log/syslog`.
• Also, make sure we are running the latest stable versions of the Linux kernel, KVM, and related virtualization packages. Updates often contain bug fixes that may resolve the issue.
• Then, double-check VM configuration files for errors. Make sure resources allocated to the VM, such as CPU and memory, are within acceptable limits and properly configured.
• Furthermore, run hardware diagnostics, focusing on CPU and memory. Verify that virtualization extensions (like Intel VT-x or AMD-V) are enabled in the BIOS/UEFI settings.
• If the issue still pops up, recreate the VM from scratch or restore it from a known good backup to see if the problem continues.
• Also, check KVM documentation for specific error codes, or search community forums for similar issues. Often, error codes are well-documented with known solutions.

Example Commands for Diagnosis

To help identify the cause of the error, we can use these commands:

1. Check KVM Status:

   sudo systemctl status libvirtd
2. View VM Logs:

   sudo cat /var/log/libvirt/qemu/vm-name.log
3. Check System Logs:

   sudo dmesg | grep -i kvm

Advanced Troubleshooting Techniques

Here are a few advanced troubleshooting tips to help fix the error:

1. Use virsh for VM inspection: virsh dominfo vm-name.
2. Verify disk image integrity with qemu-img check disk-image.
3. Monitor CPU, disk I/O, and memory with tools like perf, iostat, and vmstat.
4. Check for resource bottlenecks.
5. Review dmesg logs for kernel-level virtualization issues.
6. Adjust CPU mode (host-passthrough or host-model) in the VM configuration.
7. Tweak disk cache settings and enable/disable features like nested virtualization.
8. Test changes in a non-production environment before applying them widely.
9. Examine KVM and system logs (/var/log/libvirt/qemu/, /var/log/messages, and /var/log/syslog).

Performance Optimization Tips

1. Use CPUs with Intel VT-x or AMD-V extensions and enable them in BIOS/UEFI.
2. Opt for servers with ample RAM and fast SSD storage for lower latency.
3. Allocate dedicated CPU and memory resources to avoid overcommitment.
4. Configure VMs with “virtio” drivers for optimized disk and network I/O.
5. Use control groups to limit VM resource usage and prevent resource monopolization.
6. Store VM disk images on logical volumes or dedicated partitions to minimize fragmentation.
7. Regularly apply patches and updates to the Linux kernel, KVM, and related packages.
8. Monitor resource usage trends with tools like Prometheus and Grafana to make proactive adjustments.

[Need assistance with a different issue? Our team is available 24/7.]

Conclusion

The “KVM internal error. Suberror 1” can be challenging to troubleshoot as it may be caused by one of several causes. However, by following the steps outlined above, we can systematically diagnose and resolve the issue, ensuring your virtual environment runs smoothly.

In brief, our Support Experts demonstrated how to resolve KVM internal error. Suberror 1.