NIOC and settings

[Gortee]

Good Morning,

I am working with NIOC and wanting to correctly set shares.    I currently using the default NIOC resource pools.  Of those pools I am only using:

FT 10

Management 30

Virtual Machine 40

vMotion 20

As you can see this adds up to 100.  During time of contention on a single 10GB nic they would have the following:

FT 10 1GB

Management 30 3GB

Virtual Machine 40 4GB

vMotion 20 2GB

But I have left the NIOC systems I don't use on default

iSCSI 50

NFS 50

Replication 50

Storage Area Network Traffic 50

Is NIOC smart enough to ignore these types of traffic during contention?  Again please assume a single nic for simplicity sake.   In other words does NIOC take into account only shares from traffic it sees.  e.g.

On my 10 GB it would only see 10(FT) + 30(Mgmt)+40(VM)+20(vMotion)?

Or

10+30+40+20(First set in use)+50(iScsi)+50(NFS)+50(Rep)+50(SAN)?

Thanks in advance,

J

[DavidPasek]

This is my understanding.

When contention occurs NIOC Scheduler is sending network IO to the NIC queue based on shares. So it depends on current traffic.

Let's assume your NIOC settings:

FT 10

Management 30

Virtual Machine 40

vMotion 20

When there is only FT and vMotion traffic and nothing else saturating 10Gb then FT will be able to get 3.33Gb (33%) and vMotion 6.66Gb (66%) because 10 and 20 shares are fighting for 10Gb (100%).

If another traffic type will be participating in total network traffic then ratio will be recalculated based on shares. It is all about scheduling and IO prioritization into NIC queue.

So I think that when you don't use iSCSI, NFS, and Replication traffic types it will not affect ratio of active traffic types.

However I would set not used traffic types to 0 because it can potentially eliminate traffic types which are not expected anyway.

Just my $0.02.

[Gortee]

David,

Thanks for the response.  This is how I understand it to work as well.  One point to mention is it only works on outgoing traffic and applied per nic NIOC has no control over incoming traffic so it does a great job on vMotion, FT and most management traffic but only OK on VM traffic.    I have opened a VMware case to get a clear answer on this matter.

Thanks,

J

[Gortee · Accepted solution]

Just in case someone searches for this one later here is the answer from VMware support:

NIOC only takes into account shares of resources with activity on the uplink.   If a new resource starts to become active on the uplink then new share values are formed.   Shares only take place when contention for resources is present.

So end result you if you don't use NFS storage you can leave it with default shares since they will not take resources.

Thanks,

J