The microcode for Intel Broadwell-EP/EX (BDX-ML B/M/R0, family 6, model 79, stepping 1) processors requires a kernel with specific commits present, otherwise it might result in unexpected system behaviour. In order to handle this, /usr/libexec/microcode_ctl/update_ucode script creates necessary symlinks to make it available only on kernels with the aforementioned patches present. The required patches are present in the following versions of the kernel package: RHEL 7.6: kernel-3.10.0-894 or newer; RHEL 7.5.z: kernel-3.10.0-862.6.1 or newer; RHEL 7.4.z: kernel-3.10.0-693.35.1 or newer; RHEL 7.3.z: kernel-3.10.0-514.52.1 or newer; RHEL 7.2.z: kernel-3.10.0-327.70.1 or newer. Please use the version of the kernel with the aforementioned patches when running on Intel Broadwell EP/EX processors in order to have the microcode updated. If you want to avoid late loading of this ucode for a specific kernel, please create "disallow-late-06-4f-01" file inside /lib/firmware/ directory and run /usr/libexec/microcode_ctl/update_ucode script: touch /lib/firmware/3.10.0-862.9.1/disallow-late-06-4f-01 /usr/libexec/microcode_ctl/update_ucode If you want to avoid late loading of this microcode for all kernels, please create "disallow-late-06-4f-01" file inside /etc/microcode_ctl/ucode_with caveats directory and run /usr/libexec/microcode_ctl/update_ucode script: mkdir -p /etc/microcode_ctl/ucode_with_caveats touch /etc/microcode_ctl/ucode_with_caveats/disallow-late-06-4f-01 /usr/libexec/microcode_ctl/update_ucode If you want to enforce addition of this microcode to the firmware directory for a specific kernel, please create "force-late-06-4f-01" file inside /lib/firmware/ directory and run dracut -f --kver "": touch /lib/firmware/3.10.0-862.9.1/force-early-06-4f-01 dracut -f --kver 3.10.0-862.9.1 If you want to enforce addition of this microcode for all kernels, add a line "06-4f-01" to the file /etc/microcode_ctl/force-early-microcode and run dracut -f --regenerate-all: echo 06-4f-01 >> /etc/microcode_ctl/force-early-microcode dracut -f --regenerate-all If you want avoid removal of the ucode file during cleanup, please remove the corresponding readme file (copy of this file in /lib/firmware/). See /usr/share/doc/microcode_ctl/README.caveats for additional information.