Dell Emulex Family of Adapters - Manual (Page 1024)

Emulex Drivers Version 10.2 for VMware ESXi User Manual P010087-01A Rev. A
3. Configuration
NIC Driver Configuration
1024
Enabling Jumbo Frames
Enabling jumbo frames reduces CPU utilization and is a recommended practice. To use
jumbo frames, you must increase the MTU size in the vSwitch and also in the guest
operating system. Emulex adapters support MTU sizes between 64 bytes and 9000
bytes. For optimal performance, set the MTU size to the maximum value supported by
your network environment. The desired MTU size must be configured in the vSwitch
as well as the guest operating systems. Jumbo frames are not enabled by default in ESXi
servers.
To configure the MTU size of a vSwitch using the vSphere client:
1. Select the Configuration tab.
2. Under Hardware, click Networking.
3. Under Networking, select Properties.
4. Select the vSwitch you wish to edit and click Edit.
5. Under vSwitch Properties on the General tab, set the MTU value to 9000.
To configure the MTU size of a vSwitch using the CLI, enter the following command:
esxcfg-vswitch -m 9000 vSwitch1
Setting the MTU Size for a Linux Guest Operating System
To set the MTU size in each Linux guest operating system to 9000, run the following
command:
ifconfig eth<N> mtu 9000
where <N> is the number of the Ethernet interface on which you are working.
Setting the MTU Size for a Windows Guest Operating System
To set the MTU size in each Windows guest operating system:
1. Go to the Start menu and select Control Panel > System.
2. Select the Hardware tab and open Device Manager.
3. Expand the Network Adapters heading.
4. Right-click the appropriate NIC, and select Properties.
5. Select the Advanced tab and set the MTU value.
Using the Port Statistics Counters
You can view all of the port statistics counters maintained by the adapter’s Ethernet
driver for potential performance issues. Excessive drop or error counters are an
indication of a bad link or defective hardware.
To view the statistics of the vmnics on the ESXi host, run the following command:
# vsish -e get /net/pNics/<vmnicx>/stats
where <vmnicx> is the corresponding interface.
To view the port statistics counters on Linux guest VMs on ESXi 5.0 and 5.1, run the
following command: