StarWind V2V Conversion Stuck at 99% – Troubleshooting Help Needed

[stevediaz]

Hello

I'm trying to convert a VMware VMDK to Hyper-V VHDX using StarWind V2V Converter; but the process consistently stalls at 99%. The conversion appears to be running smoothly until the final step, where it hangs indefinitely. I've tried different source and destination storage locations, but the issue persists.

I’ve checked for disk space and ensured that no other processes are interfering. The logs don’t show any clear errors, but I suspect there may be an issue with sector alignment / disk fragmentation. Has anyone else encountered this issue, and are there any workarounds to force completion? Checked https://forums.starwindsoftware.com/viewtopic.php?t=6638 documentation guide but still need advice .

Would adjusting the conversion mode (thin vs. thick provisioning) or using an alternative output format help? If anyone has successfully resolved this problem, I’d appreciate any troubleshooting tips or insights!


Thank you !

[yaroslav (staff)]

Welcome to StarWind Forum.
Can I please have the conversion logs? They are normally under C:\Program Files\StarWind Software\StarWind V2V Converter\logs

Would adjusting the conversion mode (thin vs. thick provisioning) or using an alternative output format help?

Yes, you could try.

[EstherHaugland]

I had a similar problem with StarWind, and tried changing from thin to thick provisioning and it worked fine.

[yaroslav (staff)]

Welcome to StarWind Forum!
Try the latest build (I hope the issue is fixed )

[evelynwang]

I am having the same problem converting VMDK to VHDX using StarWind V2V Converter.
The process stops at 99% even though there are no obvious errors in the log. Has anyone tried using the command line (CLI) instead of the GUI? Is there a performance difference?
Does the log record sector alignment information? I suspect fragmentation of the source drive.

[yaroslav (staff)]

Please share the logs.

[holeioonline]

In many cases, choosing Thick mode instead of Thin will result in a successful completion. Although it takes up more space, it is more stable.

[yaroslav (staff)]

Good point.
Thick disk is better imo.

[jonesnatelye]

Hello

I'm trying to convert a VMware VMDK to Hyper-V VHDX using StarWind V2V Converter; but the process consistently stalls at 99%. The conversion appears to be running smoothly until the final step, where it hangs indefinitely. I've tried different source and destination storage locations, but the issue persists.

I’ve checked for disk space and ensured that no other processes are interfering. The logs don’t show any clear errors, but I suspect there may be an issue with sector alignment / disk fragmentation. Has anyone else encountered this issue, and are there any workarounds to force completion? Checked https://forums.starwindsoftware.com/viewtopic.php?t=6638 documentation guide but still need advice .

Would adjusting the conversion mode (thin vs. thick provisioning) or using an alternative output format help? If anyone has successfully resolved this problem, I’d appreciate any troubleshooting tips or insights!


Thank you !

I’ve seen this happen before—StarWind V2V sometimes hangs at 99% when finalizing metadata. A couple of things that usually help: try switching to “thick” provisioning instead of “thin,” and make sure you run the converter with admin rights. If it still hangs, converting first to a plain VHD (not VHDX) and then using Hyper-V Manager or PowerShell to convert VHD → VHDX often bypasses the issue.