How many NICs?

[ANorton]

I have a few ESX hosts and each server has about 10-12 NICs in them. I try to seperate them into groups such as 1 NIC for SC, 1 NIC for ISCSI, 4 NICs for 1GB connections, 4 NICs for 100MB connections. I tend to do this because i get nervous having more than 1 or 2 VM's running on a single NIC.

I wanted to get peoples thoughts and ideas on how many NIC's is recommended or used for most circumstances and whether or not It is good or bad to have a lot of VM's per NIC.

Thanks

Aaron

[piaroa]

Hey there,

It's always recommended to have 2 or more NICs per vSwitch.

A typical config would be vSwitch0: SC 2 NICs, vSwitch1: NFS/iSCSI 2 or more NICs, vSwitch2: VMotion, FT 2 NICs, and vSwitches x for VM traffic with at least 2 NICs.

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[ANorton]

Interesting.

We do not currently use FT but I have never though about putting VMotion on a seperate NIC, I didn't even know you could actually do that as I enable VMotion for all my NICs.

[dtracey]

Hi there - it depends on your underlying network configuration and your design goals.

NICs are rarely a performance bottleneck, so as long as you have at least a pair supporting a given network that is usually fine. If you can spare the physical NICs, you have an added layer of segregation between your networks, over and above VLANning.

For example with 10 12 physical NICs in an iSCSI setup i tend to use the following:

SC (ESX) / Management Network (ESXi) = 2 x NICs (separate vSwitch & vLAN)

vMotion Network = 2 x NICs (if not just VLAN'd from SC / Mgmt Network)

iSCSI network = 2 x NICs (1 NIC per vSwitch / VMkernel port)

Virtual Machine (Production) Network(s) = 2 x NICs :smileyplus:

I usually separate the tiers of VM networks through the use of VLANs, except where VMs have different security requirements (e.g in a DMZ), in which case i'll use separate physical NICs, if not a separate host altogther.

Dan

[piaroa]

Yeah, VMotion can and will use a lot of bandwidth depending on the configuration of the VMs you migrate (or DRS migrates for you).

It's a best practice to create a vmkernel port on a dedicated vSwitch for VMotion, and in theory another dedicated vmkernel for FT, but since I don't run very many FT protected VMs, I just throw both in the same vSwitch.

If this post has been helpful/solved your issue, please mark the thread and award points as you see fit. Thanks!