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Bulletin That Matters for ESXi Networking

If you are like me, it may seem that there is simply too much e-mail to keep track of. Here's one that caught my eye: an important product bulletin about a potentially urgent driver issue for ESX and ESXi installations that utilize a Broadcom interface with the BCM57711 chipset. This issue posted on HP’s Web site is applicable to VMware ESX and ESXi systems version 4.0 Update 1.

The basic issue is that the driver steps down the network queue depth to a value of 1 with the driver configuration that comes with this version of ESX and ESXi. The HP support document has steps to correct the issue, but this is concerning as it applies to a number of popular models of servers. Just from the HP line, this includes many of the ProLiant DL, BL and ML series systems.

The resolution is to use the esxcfg-module command to pass a new value to the driver’s running configuration. The HP support document points to a VMware readme file that has options to correct the running configuration for the driver instance loaded on the ESX or ESXi host. A reboot is required to make the change take effect and of course, a test environment would be a good idea to ensure that all functionality works as expected before you return each system to a cluster to host virtual machines.

To determine if the BCM57711 chipset is in use, there are two places to look on a host. The first is to look in the Network Adapters section of the vSphere Client for an ESX or ESXi host. The other options is to run “esxcfg-module –l” (the list parameter) and see if the bnx2x instance is loaded among all of the active modules. Fig. 1 shows a line of the esxcfg-module command with the list parameter, with bnx2 (non-effected controller) and e1000e (Intel controller) appearing in the list.

Running esxcfg

Figure 1. Listing the controllers using the esxcfg module. (Click image to view larger version.)

This is potentially a big issue and I’m going to get into testing right away to see if I have an affected system.

Have you made this tweak to your environment? Share your observations here.

Posted by Rick Vanover on 09/14/2010 at 12:47 PM


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