Number of VM´s on one vSwitch

[huka]

Hi Community,

are there any suggestions from VMware how many VM´s could be connected to one vSwitch without affecting perfomance ?!?

I´ve connected 4 Windows Servers with 2x 1Gbit Connection (Failover) to my Network,one of the Servers is a important and highly frequented Database Machine. Sometimes i got little performance problems on the database server, may it be that the network connection is overloaded (the 3 other Machines are not soooo highly frequented)?!?

Thanks

[weinstein5]

Can you provide more information on your configuration - like how many physical NICs are ocnnected to your vSwitch? How are your VMs configured - how many vCPUs and memory? What is the ocnfiguration of your ESX server - cpus/cores and emmory?

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[huka]

2 physical NIC´s are connected to the vswitch (everyone with 1Gbit) standard configured for Failover. on this vswitch i´ve got 4 Windows 2003 Server running (every Server itself got a Gbit Network Connection). The main server where i got the problem is configured with 2 vCPU´s (Xeon 2,493 GHz) and 2048 MB Memory. The ESX itself got 8 GB Memory and a Dual Xeon QuadCore CPU. The other virtual servers are not so high dimensioned as the main machine (the most have 1CPU, 512-1024 MB memory)!!!

Thanks

[MauroBonder]

the vmware tools its installed in all vms ?

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[huka]

yes, installed....

[MauroBonder]

Only for you knowledge, how i dont know if you use SQL.

Best Practices for SQL Server in VMware

http://communities.vmware.com/docs/DOC-8964

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[huka]

Hi, thanks, i´ve read the suggestions, but in the end I dont think that anything is misconfigured...

Does nobody know if 4 Windows Machines are probably too much for one 1Gbit vSwitch (or if it could be) ??? I thought about this, because before the Machines become virtual,3 of them are using there own Gbit uplink to my network, and now they´re Sharing one together ?? Further ideas ??

Thanks

regards

[VMmatty]

You won't know if networking is the performance bottleneck unless you look at the utilization. From within the VI Client, click on the host and then select the Performance tab. Change the view to Network and take a look at the overall utilization. Remember to go by the actual numbers presented at the bottom rather than the size of the spikes since the chart itself adjusts based on the metrics.

See if you can match up the times where you experience performance problems in the VM with high network utilization. Do the same for CPU, memory, and disk. In my experience SQL servers can be affected by disk more so than by network, not to mention CPU and memory. I would start with the performance charts and see if that can help you narrow down the cause.

Both NICs are in the vSwitch but only one is active and the other is standby? Is there a reason why you've configured it in this way? Both NICs can be active in the vSwitch and you will still have failover should one of them go down.

[huka]

You mean I should configure the 2 Adapters for Load Balancing, right...

Thanks

[TomHowarth]

Personally I only use Failover when I am NIC Contended, as a way to provides some data seperation between VMKernel and SC networks and never on production networks running VM's your networks should be configured to run is Load Balanceing based on an IP hash.

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Tom Howarth VCP / vExpert

VMware Communities User Moderator

Blog: www.planetvm.net

Contributing author for the upcoming book "[VMware vSphere and Virtual Infrastructure Security: Securing ESX and the Virtual Environment|http://my.safaribooksonline.com/9780136083214]”. Currently available on roughcuts

[huka]

Hi, thanks, for better understanding: that means that you only have the Load Balancing Box checked (in the configuration Tab), and not both (Balancing and Failover ), right ??

[TomHowarth]

yes, that is correct

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Tom Howarth VCP / vExpert

VMware Communities User Moderator

Blog: www.planetvm.net

Contributing author for the upcoming book "[VMware vSphere and Virtual Infrastructure Security: Securing ESX and the Virtual Environment|http://my.safaribooksonline.com/9780136083214]”. Currently available on roughcuts

[huka]

Have you configured the vSwitch for COS and VMKernel also this way ??

[TomHowarth · Accepted solution]

Only when I am NIC constrained. I tend to advice enough NICs to do the Job with ful reslience and etc, but with blades etc you are some time forced to introduce portgroups into vSwitches that are disparate networks is VMK and SC. best scenario is to have each Network on its own dedicated vSwitch with a minimum of 2 NICs in Load Balanced (based in IP Hash) next option is to have vSwitch configured for two NICs in failover mode.

If you found this or any other answer useful please consider the use of the Helpful or correct buttons to award points

Tom Howarth VCP / vExpert

VMware Communities User Moderator

Blog: www.planetvm.net

Contributing author for the upcoming book "[VMware vSphere and Virtual Infrastructure Security: Securing ESX and the Virtual Environment|http://my.safaribooksonline.com/9780136083214]”. Currently available on roughcuts