Wimo
Hot Shot
Hot Shot

VMotion and VMs on same subnet

Is it just best practice, or is there a technical reason not to have the VMotion vswitch and the vswitch for VMs both on the same subnet? Everything is Gig speed in this particular scenario.

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4 Replies
VirtualNoitall
Virtuoso
Virtuoso

Hello,

I would not do that. If you have to work around using just a couple of nics then put your service console and vms on the same port and keep vmotion on it's own dedicated nic\port.

You could see issues with Vmotion performance and success\failure if your port is too busy with virtual machine data.

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esiebert7625
Immortal
Immortal

Best practice, you do not want any potential network interruptions, latency, etc. when a Vmotion is in progress.

From the admin guide...

"A dedicated network is recommended to keep virtual machine memory state secure."

"For best security, dedicate the GigE NIC to VMotion and use VLANs to divide the Virtual machine and management traffic on the other NIC."

jasonboche
Immortal
Immortal

Not only do you not want to impact the VMotion process with other network traffic, you do not want to flood your production network with the sudden burst of VMotion traffic.

To boot, if you've enabled aggressive DRS, VMotioning could be happening frequently throughout the day.

We don't want the networks intermingled in order to avoid conggestion.

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

Not only do you not want to impact the VMotion

process with other network traffic, you do not want

to flood your production network with the sudden

burst of VMotion traffic.

To boot, if you've enabled aggressive DRS, VMotioning

could be happening frequently throughout the day.

We don't want the networks intermingled in order to

avoid conggestion.

This would be the only case I can definitively see a reason for doing it.

Plus like many other cases, it all depends on your environment and how much traffic is generally crossing the NIC's to begin with. If a lot of VM's are doing a fair amount of traffic (10Mb/s+) across the VM vSwitch and you will be doing a fair amount of VMotion traffic (manual or DRS) then you will want a dedicated NIC - perhaps even on its own private subnet if your network setup can afford that.