Are single socket, single core, single thread processor systems supported on RHEL 7?

Solution Verified - Updated -

Environment

  • Red Hat Enterprise Linux 7

Issue

  • Does RHEL7 support operating with a single 1-core, 1-thread processor?

  • My computer has a single socket, single core, single thread processor. When I boot, I see an "unsupported" warning on the console like the following. Is this true?

    Detected single cpu native boot.
In Red Hat Enterprise Linux 7, single threaded, single CPU physical boot 64-bit systems are unsupported by Red Hat.  
Please refer to the Red Hat Hardware Catalog at http://hardware.redhat.com for a list of certified and supported systems.

Resolution

  • For physical hardware: Red Hat does not support a RHEL7 configuration with a single logical processor
    (i.e., as above: 1 single-core CPU with a single thread)

  • For virtual guests running RHEL7: single-CPU virtual guests are still supported

Root Cause

  • This configuration is not supported by Red Hat, as the upstream kernel no longer supports this configuration

  • The message is generated at boot from this function:

    static void rh_check_supported(void)
{
    /* RHEL7 supports single cpu on guests only */
    if ((cpumask_weight(cpu_present_mask) == 1) && !x86_hyper &&
        !cpu_has_hypervisor && !is_kdump_kernel()) {
        pr_crit("Detected single cpu native boot.\n");
        pr_crit("Important:  In Red Hat Enterprise Linux 7, single threaded, single CPU 64-bit physical systems are unsupported by Red Hat. Please contact your Red Hat support representative for a list of certified and supported systems.");
    }
...

This solution is part of Red Hat’s fast-track publication program, providing a huge library of solutions that Red Hat engineers have created while supporting our customers. To give you the knowledge you need the instant it becomes available, these articles may be presented in a raw and unedited form.

Comments