Question

Recommended switch port buffer size

  • 2 December 2019
  • 3 replies
  • 2019 views

Is there a minimum or recommended switch port buffer size? I plan on using eth0 and eth 1 to be connected to two different 10G switches but was wondering if there is a minimum buffer size or switch port requirement?


3 replies

Userlevel 3
Badge +4

Hi @David L. 

You can read the AHV Networking best practices guide to better design your network infra for Nutanix HCI.

this is from the best practices guide above :

“To prevent packet loss from oversubscription, avoid switches that use a shared port-buffer architecture.” 

we don’t have an exact port buffer size recommendation. 

 

Normally with HCI and SDS deployments, it is good to use Line-rate, non-blocking switches with larger buffers for production workloads.Use an 802.3-2012 standards-compliant switch that has low latency, cut-through design and provides predictable, consistent traffic latency.

Hope this helps

BR

Userlevel 3
Badge +3

@David L. Most modern switches would not have any issues. But connecting to 10GB fabric extenders (FEX) is not recommended. See the link:

https://portal.nutanix.com/#/page/kbs/details?targetId=kA032000000TT4kCAG

If anything, you may occasionally need to change the buffer size for the Nics on the hyperviosr hardware side. Please review:

https://portal.nutanix.com/#/page/kbs/details?targetId=kA03200000099tuCAA

Based on document above, the number you look for might be 4096 bytes, but as I mentioned I would not change things on switch side, as I mentioned most switches should be able to handle the type of traffic hyper converged systems will generate.

 

Regards,

 

-Said

 

Thank you!

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