Troubleshooting Subscription Manager in Red Hat Enterprise Linux

Red Hat Subscription Management 1

to respond to problems with Red Hat Subscription Manager and Subscription Asset Manager

Red Hat Subscription Management Documentation Team

October 1, 2013

Abstract

Troubleshoot problems with the subscription-manager tool in Red Hat Enterprise Linux.

1. Troubleshooting Red Hat Subscription Manager

Because of differences in other services, features in Red Hat Subscription Manager, and environments, there are some bugs or limits to functionality for Red Hat Subscription Manager. This section contains some workarounds and troubleshooting information from some of these issues.

1.1. Red Hat Enterprise Linux 5.9

1.1.1. Guest Fact Shows UUID Unknown

For virtual guests, the Subscription Manager daemons use dmidecode to read the System Management BIOS (SMBIOS) value, which is used to retrieve the guest UUID. On 64-bit Intel architecture, the SMBIOS information is controlled by the Intel firmware and stored in a read-only binary entry. Therefore, it is not possible to retrieve the UUID or set a new and readable UUID.
Because the guest UUID is unreadable, running the facts command on the guest system shows a value of Unknown in the virt.facts file for the system (virt.uuid: Unknown). This means that the guest does not have any association with the host machine and, therefore, does not inherit some subscriptions.
The facts used by Subscription Manager can be edited manually to add the UUID:
  1. Obtain the guest name or guest ID.
  2. On the virtual host, use virsh to retrieve the guest UUID. For example, for a guest named rhel5server_virt1: 
    virsh domuuid rhel5server_virt1
  3. On the guest, manually create a facts file: 
    vim /etc/rhsm/facts/virt.facts
  4. Add a line which contains the given UUID. 
        {
      "virt.uuid": "$VIRSH_UUID"
      }
Creating the facts file and inserting the proper UUID means that Subscription Manager properly identifies the guest rather than using an Unknown value.

1.2. Red Hat Enterprise Linux 6.2

1.2.1. Manually Setting a Preferred Operating System Release

Beginning in Red Hat Enterprise Linux 6.3, Red Hat Subscription Manager could set a preferred operating system version to use to limit automatic updates for a system. This is one of several preferences that can be set to use for autoattaching subscriptions. However, it is not possible to set a preferred operating system through Red Hat Subscription Manager on older versions of Red Hat Enterprise Linux.
The system can be restricted to a certain operating system version on Red Hat Enterprise Linux 6.2 by editing the yum configuration. For example, to limit yum updates to 6.2-version packages: 
[root@server ~]# echo 6.2 > /etc/yum/vars/releasever