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My configuration is: IBM X3850M2 with 4 Six Core CPU, 128 Gb RAM, 3x dual port network Intel Corporation 82571EB Gigabit Ethernet Controller

For testing I created only 2 VM (Server 2008) which are both using the same vSwitch ( witk vmnic1 and vmnic2). Both phyisical networks are connected to 1Gb/s switch.

If I copy large file (database backup file aprox. 4GB) from one phyisical server (also connected via 1Gb/s switch) to one VM Server 2008 I get maximum transfer speed about 20 MB/s.

When I copy large file (database backup file aprox. 4GB) between both Server 2008 (trafic should go only between internal vSwitch) I get maximum transfer speed about 33 MB/s.

Both servers are using new VMXNET3 driver (10Gb/s) and the speed are the same if I use VMXNET2 driver. Network utilization within Server 2008 with VMXNET2 driver is only betwen 20% and the CPU utilizaton is always 100% when I do some kind of copying.

Do not get me wrong, but I expected much more network thruput.

Do you get similar transfer rates or is it something wrong with my implementation?

Thank you for any kind of help

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What sort of storage is there within the server? – mrdenny Jan 21 '10 at 9:36
up vote 0 down vote accepted

Something is wrong here, have you checked if your MAC addresses of the adapters are unique?

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I'd suspect that the two servers have virtual disks on the same physical disk system.

You're essentially benchmarking your storage sub system switching between read and write with a seek in-between.

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