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KML201110141
Contributor
Contributor

Bandwidth issues

Hi, i'm kind of a newbie in the VMware field, i currently have an ESX cluster containing 3 ESX, they are manage by a vCenter on a Windows Server. They all are connected via a Cisco Stackwise and all the interface are Gbits. About the storage, i'm using afiber channel SAN.

I'm currently running some performances test and for example when i tried to copy an iso file ( 8 GB) form a VM inside an ESX toward a VM inside the same ESX, but in a different VLAN, the traffic goes and is routed by the Cisco, my probleme is that the copy speed is only about 30MB/s which i don't understand. I don't think networking is the issue and i will be running some test on the SAN.

If someone already experienced something similar, i'd like to know, thanks in advance.

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idle-jam
Immortal
Immortal

i felt 30MB/s on Gigabit is a very good speed and i believe most will agreed with me

dquintana
Virtuoso
Virtuoso

Welcome to forums KML

This is a real good performance, but try the copy between vms and between vm and physical pc.

Diego

Ing. Diego Quintana - VMware Communities Moderator - Co Founder & CEO at Wetcom Group - vEXPERT From 2010 to 2020- VCP, VSP, VTSP, VAC - Twitter: @daquintana - Blog: http://www.wetcom.com-blog & http://www.diegoquintana.net - Enjoy the vmware communities !!!

KML201110141
Contributor
Contributor

Thanks for yours answers. I reach this conclusion too, i found a VMware white paper showing benchmark with netperf. They were divided into three, default, file and bulk.

http://www.vmware.com/pdf/esx_network_planning.pdf

I made some test with netperf and i reach pretty much the same throughout as VMware benchmark. I found a way to increase a little bit this bandwidht, for example with an FTP transfert, i changed the buffer from 64k to 128k and  i reached 50MB/s.

I guess i just thought that Gbit would offer more bandwidht. I'm currently doing an intership and my main goal is to set up and optimise a OS streaming system based on WYSE WSM server, it is already implenmented in a classroom but it's kind of long to boot up (5 minutes). That why i performed a benchmark of the actual network before changing anything.

Now if it's not the network, i'll have to find a way to optimise it Smiley Happy

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KML201110141
Contributor
Contributor

BTW, the copy was between a VM and a VM but on different switch. I tried between a VM and a physical computer, i got about 16 mo/s, probably because of the hard drive. I will try tomorrow between two VMs on the same vSwitch without going through the network.

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KML201110141
Contributor
Contributor

Does setting up a port channel on the Cisco and a load balancing based on IP hash on the vSwicth would help ad increase this bandwidth ?

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Virtualinfra
Commander
Commander

Test with this .

Create a virtual switch internally and put 2 Vm in that with same vlan.

now try copying the data see the performance, if this good.

Then you need to work with network about the bandwidth.

See how many nics are active and though which nic both the VMs are communicated to outer network using esxtop and option n

you can easily analysis and fix this in this way.

Thanks & Regards Dharshan S VCP 4.0,VTSP 5.0, VCP 5.0
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