What you’re seeing
- Live migration fails with "Virtual machine migration operation failed" and Event 21026 in the Hyper-V logs.
- The VM stays on its original host, so maintenance or patching cannot proceed.
- Some VMs migrate successfully while others fail between the same hosts.
- Failover Cluster Manager shows the migration as failed without a clear reason.
Common causes
Every environment is different, but these are the causes our engineers find most often:
- The destination host lacks the same virtual switch name the VM is connected to.
- The live migration network is misconfigured or blocked by a firewall.
- Authentication between hosts using CredSSP or Kerberos is not set up correctly.
- The VM has a mounted ISO, pass-through disk or other host-specific resource.
- The destination host has insufficient memory to accept the VM.
Why it matters
Live migration is what lets a cluster be patched and maintained without shutting down business services. When it fails, IT must either delay security updates or schedule downtime for every VM, both of which carry cost and risk. If a host fails while VMs cannot be moved, the cluster loses the high-availability benefit it was built for.
How AskTechGurus fixes it
Skip the trial and error. A certified engineer works on your actual system, finds the root cause, and fixes it properly.
Tell us what’s happening
Submit a ticket in about two minutes. Paste the error, describe what changed, and pick your tier. No charge to submit.
A certified engineer diagnoses it
A vetted, US-based systems engineer claims your ticket, usually within minutes during business hours, and investigates over a secure remote session you can watch and end at any time.
Fixed and verified with you
The engineer resolves the root cause and confirms with you that it’s working. You don’t just get a workaround, and you get a plain-English summary of what was wrong.
Pay only when it’s resolved
Fixed price from $99, invoiced only after you approve the fix. If it isn’t resolved, you don’t pay.
Frequently asked questions
Is the cluster broken?
Usually not. The failure is typically a configuration mismatch between hosts or VMs, rather than a fault in the cluster as a whole.
Can you troubleshoot this remotely?
Yes. Our certified US engineers review Hyper-V cluster migration problems in remote secure sessions, starting from $99, and you pay only when it is resolved.