Ethernet configuration files renamed on Cisco UCS systems when hardware is changed

Solution Verified - Updated -

Environment

  • Cisco UCS blades
  • Red Hat Enterprise Linux 5.3 or newer

Issue

  • The /etc/sysconfig/network-scripts/ifcfg-ethX Ethernet configuration files are renamed to ifcfg-ethX.bak when network hardware is changed on Cisco UCS blades, even when properly configured service profiles are in use. Service profiles should prevent this change as they cause the same MAC address to be advertised to the system at all times, even if the underlying hardware changes.

Resolution

  • Removing the .bak extension from the files will restore the system's network connections to working order.
  • A fix for the issue is being investigated in this Bugzilla ticket: https://bugzilla.redhat.com/show_bug.cgi?id=636263

Root Cause

  • Kudzu is detecting a change in the PCI subvendor ID for the network hardware when the hardware is replaced.

  • The subvendor ID change leads kudzu to believe that the hardware has changed, even though the hwaddr entry in the ifcfg-ethX file (MAC address) has not, which causes the existing network configuration files to be renamed in preparation for new files to be generated.

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