Why paravirtualized xen based virtual machine is not able to perform updates when registered using subscription-manager?

Solution Unverified - Updated -

Environment

  • Red Hat Enterprise Linux 5 and 6
  • Xen
  • Red Hat Subscription Manager

Issue

  • Why paravirtualized xen based virtual machine is not able to perform updates when registered using subscription-manager?

Resolution

  • There is no DMI mechanism for xen paravirtualized guests, however it gets identification from other means, mainly a UUID injected into the sysfs interface.

  • Need to run virt-who service on Xen hypervisor for this particular issue with following commands:

# yum install virt-who
# chkconfig virt-who on
# service virt-who start

-Once virt-who service send the virtual machine UUIDs to the Red Hat Customer portal, paravirtualized guest will be able to subscribe to required subscriptions.

Root Cause

  • virt-who service was not running on Xen hypervisor.

Diagnostic Steps

  • RHSM logs showing following dmi information errors in xen based paravirtualized virtual machine:
[WARNING]  @hwprobe.py:97 - Error reading system DMI information with <built-in function connector>: [src/dmidecodemodule.c:317] Erro
r decoding DMI data
[WARNING]  @hwprobe.py:90 - Error reading system DMI information: 'NoneType' object has no attribute 'items'
[WARNING]  @hwprobe.py:407 - Error reading system DMI information: /dev/mem (mmap): Bad address
/dev/mem (mmap): Bad address
/dev/mem (mmap): Bad address
  • Component
  • xen

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