ESXi 8.0 to Hyper-V conversion slow

[microkid]

Trying to convert some VM's from ESXi 8.0 to Hyper-V (on Windows 11).
Conversion takes forever. Network speed is only 2-3Mbps.
Both ESXi host and Win11 are in the same network, same subnet and next to eachother, connected over 1Gbps.
Tried to convert a VM, single disk, convert to local disk. No matter the option, the speed is slow.
Any suggestions?

Log:
The log file name: 'logs\V2V_Log-20240713-111324.log' (PID 12200)
7/13 11:13:24.222 2eb4 Facility ???INFO: CV2V_ConverterApp::InitInstance: SetDllDirectory: C:\Program Files\StarWind Software\StarWind V2V Converter\lib
7/13 11:13:24.222 2eb4 Facility ???INFO: CV2V_ConverterApp::InitInstance: File Version: 9.0.1.509
7/13 11:13:24.225 2eb4 Facility ???INFO: CV2V_ConverterApp::InitInstance: Load language IDR_XML_ENGLISH
7/13 11:13:24.225 2eb4 Facility ???INFO: CV2V_ConverterApp::InitInstance: Set current language English
7/13 11:13:24.228 2eb4 Facility ???INFO: CPS_V2V_Converter::CPS_V2V_Converter: Version MajorVersion 10, MinorVersion 0, BuildNumber 22631
7/13 11:13:24.235 2eb4 Facility ???INFO: WrapperHyperV::WrapperHyperV: LoadLibrary C:\WINDOWS\system32\wbem\wmiutils.dll - 3a1d0000
7/13 11:13:24.236 2eb4 Facility ???INFO: WrapperHyperV::WrapperHyperV: LoadLibrary C:\WINDOWS\system32\wbem\wmiutils.dll - 3a1d0000
7/13 11:14:07.939 2eb4 Facility ???INFO: ICPPage::OnWizardNext: SetActivePage - eESXConnection
7/13 11:14:16.154 2eb4 Facility ???INFO: WrapperESXI::connect: m_url - https://192.168.1.200/sdk
7/13 11:14:16.201 2eb4 Facility ???INFO: WrapperESXI::connect: fullName - Administrator, key - 524138b4-0322-0679-9464-aa6a3781e0ae
7/13 11:14:16.201 2eb4 Facility ???INFO: ICPPage::OnWizardNext: SetActivePage - eInputVM
7/13 11:14:17.117 2eb4 Facility ???INFO: VMConverter::ESXIConverter::GetHostListInfo: ESX version: 8.0.3
7/13 11:14:26.742 2eb4 Facility ???INFO: ICPPage::OnWizardNext: SetActivePage - eLocationTo
7/13 11:14:48.322 2eb4 Facility ???INFO: ICPPage::OnWizardNext: SetActivePage - eHYPERVConnectionTo
7/13 11:14:50.540 2eb4 Facility ???INFO: WrapperHyperV::connect: Host - \\localhost\root\virtualization\v2
7/13 11:14:50.618 2eb4 Facility ???INFO: WrapperHyperV::init_version: HyperV version: 10.0.22631
7/13 11:14:50.618 2eb4 Facility ???INFO: ICPPage::OnWizardNext: SetActivePage - eOutputVM
7/13 11:15:21.926 2eb4 Facility ???WARNING: ConfigNewHyperVVM::OnOK: The virtual machine path is empty.
7/13 11:16:20.548 2eb4 Facility ???WARNING: CPPOutputVM::OnButtonBrowseClick: Fill up GUID is fail
7/13 11:16:22.178 2eb4 Facility ???INFO: ICPPage::OnWizardNext: SetActivePage - eOptionsHyperV
7/13 11:18:08.350 2eb4 Facility ???INFO: ICPPage::OnWizardNext: SetActivePage - eVolumeSelectVM
7/13 11:18:17.960 2eb4 Facility ???INFO: ICPPage::OnWizardNext: SetActivePage - eConverting
7/13 11:18:17.975 14c0 Facility ???INFO: CPPConverting::Convert: InConvertType: 5, OutConvertType: 7
7/13 11:18:17.975 14c0 Facility ???INFO: CPPConverting::ConvertDisks: pathInput: [NVME] Win10 Sandbox/Win10 Sandbox-000001.vmdk, pathOutput: C:\VirtualMachines\Win10 Sandbox\Virtual Hard Disks\Win10 Sandbox-000001.vhdx
7/13 11:18:18.084 14c0 Facility ???INFO: ESXVmdk::ParseFile: sFilename - [NVME] Win10 Sandbox/Win10 Sandbox-000001.vmdk
7/13 11:18:18.084 14c0 Facility ???INFO: ESXVmdk::ParseFile: m_cvmxSpec - moref=10
7/13 11:18:18.084 14c0 Facility ???INFO: ESXVmdk::ParseFile: sslThumbprint - 60:4C:EA:1F:9F:FF:B0:63:53:0F:53:41:BD:5B:B5:8B:F6:59:D1:0C
7/13 11:18:19.573 14c0 Facility ???INFO: CPPConverting::ConvertDisks: CreateInputImage: 0
7/13 11:18:20.944 14c0 Facility ???INFO: CPPConverting::ConvertDisks: CreateOutputImage: 0
7/13 11:19:16.213 43e8 Facility ???INFO: VMConverter::ESXIConverter::Connection::<lambda_8874940e4602bbfc5e7b4b277e23eb86>::operator (): Timeout ESX connection
7/13 11:27:20.335 14c0 Facility ???WARNING: CPPConverting::ConvertImage: Cancel
7/13 11:27:20.343 14c0 Facility ???ERROR: CPPConverting::ConvertDisks: ConvertImage - 1
7/13 11:27:20.358 14c0 Facility ???WARNING: CPPConverting::Convert: CANCEL
7/13 11:27:26.146 2eb4 Facility ???INFO: ICPPage::OnWizardNext: SetActivePage - eLocation
7/13 11:27:28.459 2eb4 Facility ???INFO: ICPPage::OnWizardNext: SetActivePage - eESXConnection

[yaroslav (staff)]

Hi,

Please share more details.
Any firewalls or vLANs configured?
What is the storage configuration on the Destination and Source sides?

[microkid]

Hi,

No vlans. Storage on both sides is NVMe. Normally, I can copy data to and from ESXi at Gbit speed.

[yaroslav (staff)]

I will touch-base with Dev team to see if conversion can be optimized.
This might take some time.

[microkid]

Ok. some update. I did some more testing and found out that the Intel Network driver on the Win11 device was causing speed issues. After updating it to v29.1, speed was normal again. Before the update, copy speeds from any source on my network to the Win11 device was limited to approx 20MB/sec. After the update, it came back to 100MB/sec. I then started a V2V session and it finished succesfully in 30 minutes.

But ... V2V is still slow. Datacopy is only 20-30MB/sec. At the same time, I can copy any VMDK file from the ESXi server to the Win11 device (using WinSCP) with 100MB/sec. It would be nice if V2V can improve network speeds.

[yaroslav (staff)]

Thanks for your update.
V2V is a single-threaded app plus the library used for conversion might be the bottleneck too.
We are working on improving the performance.

[microkid]

Thanks for your update.
V2V is a single-threaded app plus the library used for conversion might be the bottleneck too.
We are working on improving the performance.

hi, I know it is singe threaded. But the cpu never came over 2-3% during migration. Even with the process priority set to "high", it was not faster. So I assume the library might need some optimization.

[yaroslav (staff)]

Sorry for the delay.
I have filed an improve request on my end. Hope for some optimizations in builds to come.
Thanks again for your comment and cooperation!

[dianereese]

If Jumbo Frames are enabled on the ESXi and Windows hosts, ensure they are consistently configured across the network (e.g., MTU size of 9000). Mismatched MTU can lead to packet fragmentation and performance issues.