System registered and subscribed using subscription-manager, but unable to run the command "rhn_check -v".

Solution Unverified - Updated -


  • Red Hat Enterprise Linux 5.7 and newer
  • Red Hat Enterprise Linux 6.1 and newer
  • System registered using Red Hat Subscription Manager (RHSM)


  • rhn_check -v command fails on system registered using Red Hat Subscription Manager (RHSM):
# rhn_check -v
ERROR: unable to read system id


  • There is no substitute command, but following command can be used to check the available updates for a system registered using RHSM.
# yum check-update

Root Cause

  • rhn_check command is used to pick up erratas,package scheduled through RHN Classic portal for system registered under RHN Classic. This command is executed by rhnsd service on systems manged through RHN Classic.
  • In subscription manager there is no option to schedule package updates through portal . So system managed through Subscription Manager rhsnd service and rhn_check command is not available.
  • rhn_check command does not work with Red Hat Subscription Manager.
  • Component
  • yum

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as usual the biggest ball ache with RHEL is the tortuously complex subscription system and a support network embroiled in a barrage of intransigence