Network performance issue (tx only)

[citybird]

Hi

We have noticed that our upload from our three ESX4.0 servers is quite poor. On the Hardware-side, all three servers are HP Proliant DL380 G5, with two additional network cards (Intel EXPI9402PTBLK Pro), with two ports per card, giving each server a total of 6 network ports.

Our network-configuration is that the two builtin-ports are teamed for VMware Kernel and the Service Console, three of the four additional ports are teamed for LAN-Traffic, while the fouth is used for DMZ-Traffic. We are only complaining about the LAN-Traffic speed.

I measured the speeds with netio. The result is (on both, Windows and Linux guest OSes), that the download speed on the Guest is roughly 80MB/s, which is decent for our Gbit-Lan. However, the upload is stuck around 10 - 13MB/s, which is rather poor. We thought that this might also be a Switch issue, so we tried a physical HP-Server (ProLiant DL360 G4) which is running Windows Server and is connected to the same switch. This machine gives us 80MB/s in both directions.

Any ideas what we could do to improve our network performance?

[admin]

Which network adapters are you using? See: Choosing a network adapter for your virtual machine,

Rick Blythe

Social Media Specialist

VMware Inc.

[citybird]

We are using E1000 and VMXNET3, but this does not make a notable difference. It seams that VMXNET3 is slightly faster in both directions, but sending is still significantly slower than receiving. Here's a result-screen of a test we've made.

NETIO - Network Throughput Benchmark, Version 1.26

(C) 1997-2005 Kai Uwe Rommel

TCP connection established.

Packet size 1k bytes: 65316 KByte/s Tx, 17394 KByte/s Rx.

Packet size 2k bytes: 62178 KByte/s Tx, 19588 KByte/s Rx.

Packet size 4k bytes: 63279 KByte/s Tx, 19111 KByte/s Rx.

Packet size 8k bytes: 77341 KByte/s Tx, 22257 KByte/s Rx.

Packet size 16k bytes: 80261 KByte/s Tx, 37704 KByte/s Rx.

Packet size 32k bytes: 89565 KByte/s Tx, 70087 KByte/s Rx.

Done.