Re: CAN BE USE MTU MORE THEN 9000 NFS AS PRIMARY WITH KVM HOST?

[Rohit Yadav]

Hi Sanjay,

Depending on whether you're using dedicated nics for storage traffic types or 
using management nics to also carry storage network, you can configure the nics 
with specified MTU.

For example, in my KVM based env I've cloudbr0 to carry Public and Guest 
traffic (at 1G speed) but use cloudbr1 for both management & storage traffic 
(at 10G speeds) and they use MTU 9000. As an illustration the following netplan 
configuration has eth0 and enp1s0f1 which are 10G nics of a 10G X540-AT2 PCIE 
card on the host and are part of cloudbr1 with 9000 MTU:

network:
  version: 2
  renderer: networkd
  ethernets:
    eno1:
      dhcp4: false
      dhcp6: false
      optional: true
    en112s0:
      dhcp4: false
      dhcp6: false
      optional: true
    eth0:
      dhcp4: false
      dhcp6: false
      optional: true
      match:
        macaddress: <some mac>
      set-name: eth0
      mtu: 9000
    enp1s0f1:
      dhcp4: false
      dhcp6: false
      optional: true
      match:
        macaddress: <some mac>
      set-name: enp1s0f1
      mtu: 9000
  bridges:
    cloudbr0:
      addresses: [192.168.1.10/24]
      routes:
       - to: default
         via: 192.168.1.1
      nameservers:
        addresses: [192.168.1.1]
      interfaces: [eno1, en112s0]
      dhcp4: false
      dhcp6: false
      parameters:
        stp: false
        forward-delay: 0
    cloudbr1:
      addresses: [10.10.1.10/24]
      interfaces: [eth0, enp1s0f1]
      dhcp4: false
      dhcp6: false
      mtu: 9000
      parameters:
        stp: false
        forward-delay: 0



Regards.

 


________________________________
From: Sanjay Kumar <sslinuxp...@gmail.com>
Sent: Friday, May 23, 2025 17:35
To: users@cloudstack.apache.org <users@cloudstack.apache.org>; 
d...@cloudstack.apache.org <d...@cloudstack.apache.org>
Subject: CAN BE USE MTU MORE THEN 9000 NFS AS PRIMARY WITH KVM HOST?

Hello!

We are using truenas on 1500 MTU. Can we use MTU more then 9000 as NFS
primary with KVM host?

ACS: 4.20
KVM : Ubuntu 22.04

Any help would be really appreciated.

Thank you!