poor performance between vm in same host

[claudiotinelli]

Hello all,

I've poor Network Throughput Between Virtual Machines on the Same ESX.
I've try to move my VM on another host and the problem it's the same.
If i try to test my network performance with a download's tool I discover that my Mbps is average 150 in write and 300 in read... poor for Gigabit Network.

I've try to test it into vswitch without any nics: it's the same.

I've ESX5u1, i've upgrade my vm nic's driver to vmxnet3 ... i've a lot of free CPU/RAM and resource.

If i try to perform a test witch iperf between VM and VM into same host and with default TCPwinSize (64k) it is very slow : 1 - 0,8 Mbyte/s.

If i try to perform a test witch iperf between VM and phisycal PC into same LAN and with default TCPwinSize (64k) it is 20 -30 Mbyte/s.

But,

If i try to perform a test witch iperf between VM and VM into same  host and with TCPwinSize (8 or 32 or 128 or 256k) it is very fast: 100 - 125  Mbyte/s.

If i try to perform a test witch iperf between VM and phisycal PC  into same LAN and with TCPwinSize ((8 or 32 or 128 or 256k)) it is very fast.

My usally vm is Windows2003, XP e 2008.

The problem is on all VM....

May depend from having converted the VM virtual hardware from 7 to 8; from having updated the vmware tools?

Any idea?

thanks

[rickardnobel]

claudiotinelli wrote:

If i try to perform a test witch iperf between VM and VM into same host and with default TCPwinSize (64k) it is very slow : 1 - 0,8 Mbyte/s.

....

My usally vm is Windows2003, XP e 2008.

Have you tried between two Windows 2008 VMs? There is large improvements done in the TCP code in Windows between the 2003 and 2008 generation.

You could also try (just for checking the bandwidth) to use multiple sessions with iperf and see if your throughput improves: http://rickardnobel.se/archives/1186

[claudiotinelli]

No. I try it now.

But, before I upgrade ESX, VM tools and hardware version performance was highest!

[rickardnobel]

claudiotinelli wrote:

But, before I upgrade ESX, VM tools and hardware version performance was highest!

With upgrade, do you mean that the performance was higher when on ESXi 5, but before update 1?

Or when you was on ESX/ESXi 4.x?

[claudiotinelli]

... when it was on ESX/ESXi 4.x