Poor 100mbit network performance on 3.0.2 / great 1000mbit performance

[renski]

I have a vmware 3.0.2 server with latest build. I have several nics in the server, 1 is connected to a 100mbit physical switch and the other is connected to a 1000mbit physical switch.

I've been experiencing slowness on the network using the service console and any VM's on the 100mbit switch. Soon as I do a test via the 1000mbit switch I can get 50-70meg/s in both directions to the service console and to the VM's.

100mbit tests (Using FTP Client, transfer speeds vary depending on the client, SCP is worse):

Uploading to the service console/any VM from a physical server: 80-90k/s

Downloading from the service console/any VM to a physical server: 350-400k/s

1000mbit tests:

Uploading to the service console from physical server: Betweeen 50meg/s - 70meg/s

Downloading from service console - The same as above, 50-70meg/s

The 100mbit and 1000mbit ethernet are both connected to a 4 port ethernet card. I've done several tests on the 100mbit network between physical servers and they all peak at 11meg/s in both directions.

Duplex is set to FULL on vmware

[RParker]

The 100mbit and 1000mbit ethernet are both connected to a 4 port ethernet card. I've done several tests on the 100mbit network between physical servers and they all peak at 11meg/s in both directions.

12.5 Mb/s is the MAX you can get from a 100 Mb network..... So 11 Mb/s is pretty decent.

80-90k/s is pretty bad.. maybe your 100 meg network switch is saturated or the configuration isn't the same.

[Bwhite · Accepted solution]

Make sure that the physical switches are set to autonegotiate and the Networks adapters are also set the same. I have found that setting the switches manually can cause problems.

[VirtualGnana]

Hi,

Since you are using two different nics on two different switches, would suggest to check the NIC configuration in Virtual Center under Configuration --> Networking --> select the NIC connected to 100 mbps Switch and select properties --> select Network Adapters properties --> select the NIC and set the Speed and duplex according to the switch configuration.

In my case its 100 MPBS full duplex

Hope this helps

Gnan

[renski]

that fixed it.

the 1000mbit was set to autonegotiate and 100mbit was set to manual 100 Full duplex

Changed it to Auto and speeds are good now on the 100mbit!

thanks