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laserjet
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Network Utilization

Hi,

I have 5 ESX server in clusters, and enabled alarm for Network utilization for 95%. I noticed network utilization of some ESX server shoots to 600%-700%. Even I have 2 x1GB NIC on all ESX Servers.

How to check where is problem and what is causing these peeks, also combined NIC bandwidth is 2GB how ESX can pass traffice more then 2GB like 600%?

Load balancing is default port ID based. All ESX Servers are ESX 3.0.1

Thanks

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jasonboche
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Actually I was going to suggest the 600% network utilization may be traffic that is isolated to VMs on the same virtual switch on an ESX host. Remember that two VMs connected to the same virtual switch will communicate with each other as fast as the ESX host bus speed allows. Intra virtual switch traffic will not be limited to 1Gbps for the sake of emulating a physical NIC. On a powerful ESX server, network utilization on a virtual switch could exceed 1Gbps by quite a bit which could account for the 600% numbers you are seeing.

VCDX3 #34, VCDX4, VCDX5, VCAP4-DCA #14, VCAP4-DCD #35, VCAP5-DCD, VCPx4, vEXPERTx4, MCSEx3, MCSAx2, MCP, CCAx2, A+

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jayolsen
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Is the network traffic all on virtual switches between hosts? That can be faster as it might not hit the network layer.

jasonboche
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Actually I was going to suggest the 600% network utilization may be traffic that is isolated to VMs on the same virtual switch on an ESX host. Remember that two VMs connected to the same virtual switch will communicate with each other as fast as the ESX host bus speed allows. Intra virtual switch traffic will not be limited to 1Gbps for the sake of emulating a physical NIC. On a powerful ESX server, network utilization on a virtual switch could exceed 1Gbps by quite a bit which could account for the 600% numbers you are seeing.

VCDX3 #34, VCDX4, VCDX5, VCAP4-DCA #14, VCAP4-DCD #35, VCAP5-DCD, VCPx4, vEXPERTx4, MCSEx3, MCSAx2, MCP, CCAx2, A+
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laserjet
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Hi Jasonboche,

That makes sense, may be this traffic is between VM's on same virtual switch. But I want to be alarmed only when traffic is above 95% on pyhsical NIC's not within virtual switch. I want to make sure one of the VM's is not choking network traffic at physical NIC's.

Is there a way to prove that this traffic is within virtual switch and not hitting physical NIC's ever?

Thanks for your reply

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jasonboche
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I'm sure you could dig that up in VMware's documentation or on the many forum posts here in the VMTN community. I belive the ESX Advanced Technical Design Guide book also explains this. For this, you'll just have to take our word for it, otherwise, you could fire up a sniffer on your network to guarantee all that traffic you're seeing isn't coming out onto the wire from your ESX PNIC.

Jas

VCDX3 #34, VCDX4, VCDX5, VCAP4-DCA #14, VCAP4-DCD #35, VCAP5-DCD, VCPx4, vEXPERTx4, MCSEx3, MCSAx2, MCP, CCAx2, A+
laserjet
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Thanks Jas for quick reply,

I agree that this traffice is within virtual switch.

Is there a way to setup alarm on network utilization above 95% on ESX PNIC? I don't want to get alarm on virtual switch activity.

Thanks

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