On a Dell PE T610 I have Hyper-V core running, with 2 x Broadcom BCM5709C NetXtreme II GigE installed. I have noticed that copying large files 17GB for example, from a network physical server to the Hyper-V host local drive [not vm guest] is very slow in comparison to copying from Physical to Physical servers.
- Copying a 17GB file physical to Hyper-V host takes 30 minutes
- Copying a 17GB file physical to physical host takes 15 minutes
Can someone tell me exactly what registry nodes I should disable on Hyper-V NICs to improve performance. So far I have gone to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4 D36E972-E325-11CE-BFC1-08002BE10318} and set the following to 0 on both physical NICs:
- LSOv1IPv4
- LSOv2IPv6
- TCPUDPChecksumOffloadIPv4
- TCPUDPChecksumOffloadIPv6
Should I also disable *TCPConnectionOffloadIPv4 & *TCPConnectionOffloadIPv6?
Best Answer
Are you copying files from one VM to another VM on the same Hyper-V host?
If you're doing a physical to physical transfer, one disk/LUN is reading at full speed, and one is writing at full speed. If you are doing VM to VM transfers on the same storage, you can expect half the throughput because the same set of disks are doing both the reads and the writes.
If the VMs are using independent storage, are you using dynamic disks or pass-through? Dynamic disks have a lot lower overhead in Hyper-V R2, but it's not zero. I wouldn't expect a 50% drop in throughput though.