Hello,
One of my customers was working on a V2V migration of a critical virtual machine from one vCenter to the other vCenter.
Just to give a background both the vCenter servers are inside the same Datacenter and thus we suspect the transfer will be smooth and will take lesser time.
But a V2V was just giving 35-40 Mbps as the transfer rate.
Based on our calculation with this speed and the amount of data the VM had we concluded it will take around 48 hours.
Now the application team was not ready to provide such a long window and hence we had to think of an alternate.
As the V2V traffic was flowing over the management network we thought of splitting the VM into two by performing a clone of the VM and place both the VM’s on two different ESXi host.
The VM originally had 4 VMDKs, C:\, D:\, E:\ and G:\.
On the original VM we removed the last two VMDK’s from the inventory and on the clone VM we removed the first two VMDKs.
Later we initiated a V2V for both the original and cloned VM with separate VMDKs.
Since both the original and cloned VM’s were placed on two different ESXi hosts we started to get very high speed as compared to the last time.
Post successful V2V, we went to the destination vCenter server and removed the last two VMDK’s from the VM created by the source cloned VM and further added it to the VM created by the source original VM.
Later discard the VM which was created by the source cloned VM.
The virtual machine was handed over to application team to perform sanity check.
Other thing which also helped in increasing the transfer rate was disabling SSL encryption on converter server.
By default in VMware vCenter Converter Standalone 5.x and 6.0 converter worker encrypts the data stream using SSL.
Encrypting the traffic increases security, but it decreases the performance.
Below are the steps to disable encryption.
- Take a backup of the converter-worker.xml file. By default, this file is located at:
Windows 7/Server 2008 and Later – C:\ProgramData\VMware\VMware vCenter Converter Standalone
Window Vista, XP and 2003 Server – %ALLUSERSPROFILE%\VMware\VMware vCenter Converter Standalone
In older Windows versions – %ALLUSERSPROFILE%\Application Data\VMware\VMware vCenter Converter Standalone
- Open the converter-worker.xml file using a text editor.
- Locate the tag pair <useSsl></useSsl>. It is located inside the <nfc> tag and has a value of true.
- Change the value to false.
- Save and close the file.
- Restart the VMware vCenter Converter Standalone Worker service on the machine.
You can also try this if you have a stringent change window and the amount of data to transfer is high whereas the transfer rate is too low.
The customer managed to handover the VM to the application team in less than 12 hours where they were continuously getting transfer rate as 150-180 Mbps.
Hope this helps!
Virtual Reality 