I have a Dell PowerEdge R740 server with a 10GB NIC and a 10GB Switch, the VM detects the 10 Gb link but when doing speed tests with the iperf tool I don't get a measure of even close to 10 GB, the maximum it can achieve They are 900Mb, please suggest me how I can resolve this situation.
thank you
Hi, i have the same problem, i have 3 host with esxi 8.0 and one host qwith vcenter server. 10gb ethernet cards with a cisco 10gb switch and i test with iperf in two VM get the same 900mb. The VM's have the ethernet adapter VMXNET3, the esxi nic's have 10000mbps full.
Which vSphere version we are discussing?
What type of switch you have in cluster? vSwitch on each host or dVS?
Have you tried setting MTU to 9000 to enable Jumbo Frames?
I tried to change MTU to 9000 on vswitch's, same result.
I try to change to jumbo frames on switch cisco 10gb?
Hi,
did you check if your network is in a good shape?
esxcli network nic stats get -n vmnicX
Pause frames might be responsible for a lower throughput.
Configuring Flow Control on VMware ESXi and VMware ESX
And of course you should check if your LAN switch isn't the bottleneck, I assume you're not connected via a Cisco Fabric Extender.
To achieve full performance the LAN Switch should have a non-blocking architecture and a NPU shared switch buffer of at least 16 MB.
Hi, its VMware vSphere 8 Essentials Plus Kit for 3 host.
Vswitch on all host's
I test the two nics:
esxcli network nic stats get -n vmnic2
NIC statistics for vmnic2
Packets received: 244698
Packets sent: 25095
Bytes received: 42893114
Bytes sent: 35118082
Receive packets dropped: 0
Transmit packets dropped: 0
Multicast packets received: 112842
Broadcast packets received: 120895
Multicast packets sent: 0
Broadcast packets sent: 35
Total receive errors: 0
Receive length errors: 0
Receive over errors: 0
Receive CRC errors: 0
Receive frame errors: 0
Receive FIFO errors: 0
Receive missed errors: 0
Total transmit errors: 0
Transmit aborted errors: 0
Transmit carrier errors: 0
Transmit FIFO errors: 0
Transmit heartbeat errors: 0
Transmit window errors: 0
esxcli network nic stats get -n vmnic3
NIC statistics for vmnic3
Packets received: 441773
Packets sent: 200452
Bytes received: 183003408
Bytes sent: 75958843
Receive packets dropped: 0
Transmit packets dropped: 0
Multicast packets received: 113260
Broadcast packets received: 121223
Multicast packets sent: 99
Broadcast packets sent: 248
Total receive errors: 0
Receive length errors: 0
Receive over errors: 0
Receive CRC errors: 0
Receive frame errors: 0
Receive FIFO errors: 0
Receive missed errors: 0
Total transmit errors: 0
Transmit aborted errors: 0
Transmit carrier errors: 0
Transmit FIFO errors: 0
Transmit heartbeat errors: 0
Transmit window errors: 0