Cisco Cisco Nexus 1000V Switch Troubleshooting Guide
Nexus 1000v VSM and Host UUID Changes
Document ID: 116257
Contributed by Joe LeBlanc, Cisco TAC Engineer.
Aug 19, 2013
Aug 19, 2013
Contents
Introduction
VMware Issue
B200, B220, B440 M3 Blade Issue
Resolution
Relevant Logs
VMware Issue
B200, B220, B440 M3 Blade Issue
Resolution
Relevant Logs
Introduction
This document describes how the virtual supervisor module (VSM) of a Cisco Nexus 1000v Series switch
handles a change in host UUID. If the appropriate number or type of licenses is not available, traffic flow
might be interrupted.
handles a change in host UUID. If the appropriate number or type of licenses is not available, traffic flow
might be interrupted.
The VSM of a Nexus 1000v switch issues licensing to hosts based on the universally unique identifier (UUID)
of the hardware. This means that, if a host UUID changes for whatever reason, it is viewed as a new host by
the VSM. While it is unusual for a host UUID to change during its lifetime, Cisco is aware of two situations
that can cause a UUID change − a VMware software defect in ESXi 5.0 and a Cisco Unified Computing
System (UCS) firmware defect on M3 blades.
of the hardware. This means that, if a host UUID changes for whatever reason, it is viewed as a new host by
the VSM. While it is unusual for a host UUID to change during its lifetime, Cisco is aware of two situations
that can cause a UUID change − a VMware software defect in ESXi 5.0 and a Cisco Unified Computing
System (UCS) firmware defect on M3 blades.
When the UUID changes, the VSM sees the previously loaded module as a new host. The host is loaded as a
new module and assigned a new module number and new license. If no licenses are available, the host is
assigned an overdraft license; if there are no overdrafts available, the host is not assigned a license at all. If
there are production virtual machines (VMs) on this host, they can no longer pass traffic, because unlicensed
hosts cannot receive programming from the VSM.
new module and assigned a new module number and new license. If no licenses are available, the host is
assigned an overdraft license; if there are no overdrafts available, the host is not assigned a license at all. If
there are production virtual machines (VMs) on this host, they can no longer pass traffic, because unlicensed
hosts cannot receive programming from the VSM.
VMware Issue
If the system management BIOS (SMBIOS) version of the VMware ESXi 5.0 system is version 2.6 or later,
the SMBIOS UUID reported by the ESXi 5.0 host might be different from the actual SMBIOS UUID. The
byte order of the first three fields of the UUID is not correct.
the SMBIOS UUID reported by the ESXi 5.0 host might be different from the actual SMBIOS UUID. The
byte order of the first three fields of the UUID is not correct.
The SMBIOS specification extends the BIOS interface on x86 architecture systems and addresses how
motherboard and system vendors present management information about their products in a standard format.
The information is intended to allow generic instrumentation to deliver this information to management
applications that use desktop management interface (DMI), Common Information Model (CIM) or direct
access and to eliminate the need for error−prone operations such as probing system hardware for presence
detection.
motherboard and system vendors present management information about their products in a standard format.
The information is intended to allow generic instrumentation to deliver this information to management
applications that use desktop management interface (DMI), Common Information Model (CIM) or direct
access and to eliminate the need for error−prone operations such as probing system hardware for presence
detection.
The SMBIOS specification is intended to provide enough information so that BIOS developers may
implement the necessary extensions in order to allow the hardware on their products and other system−related
information to be accurately determined by users of the defined interfaces.
implement the necessary extensions in order to allow the hardware on their products and other system−related
information to be accurately determined by users of the defined interfaces.
The VMkernel interacts with the hardware that uses the CIM and passes this information up. The virtual
Ethernet module (VEM) interacts with the VMkernel in order to read the UUID information that was first
Ethernet module (VEM) interacts with the VMkernel in order to read the UUID information that was first