Red Hat Enterprise Linux 6.x guest on VMware products reports an unsupported CPU error

Solution Verified - Updated -


  • Red Hat Enterprise Linux 6.x
  • VMware ESXi Server or other VMware products certified to run Red Hat Enterprise Linux as a guest
  • New Intel CPU


  • When running Red Hat Enterprise Linux 6.x as a guest on VMware ESXi Server or other VMware products with a newer Intel CPU, the installer can stop, printing out the an error similar to the one seen here:
[Unsupported Hardware Detected]

This hardware (or a combination
thereof) is not supported by Red
Hat.  For more information on
supported hardware, please refer
  • A message similar to the ones below will be printed during boot:

    • [RHEL6.3]
    UNSUPPORTED HARDWARE DEVICE: CPU family 6 model > 59
    • [RHEL6.4 or RHEL6.5]


This issue has been fixed in kernel 2.6.32-504.el6 and the error will no longer be displayed when running Red Hat Enterprise Linux 6.6 or newer as a guest on VMware products:

If you are running earlier update releases of Red Hat Enterprise Linux 6.x on a VMware product, the UNSUPPORTED message would be a false alarm. The error dialog box can safely be ignored by pressing the OK button. The error message during boot can also be ignored.

Root Cause

The problem occurs when a customer is running VMWare as the hypervisor with Red Hat Enterprise Linux 6.x as a guest. It appears that VMWare is passing the CPU ID and other info up to the guest and Red Hat Enterprise Linux is detecting that CPU as unsupported hardware. This warning would be correct in a bare-metal environment, but it can be safely ignored if using a VMware hypervisor.

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For me, I was provided with the same error message during the kickstart process for RHEL 6.3 on a Fujitsu RX300 S8 machine.
So I switched to another terminal (ALT+F2) and opened the "syslog" file:
dmesg | grep -i unsupported -B2

Booting paravirtualized kernel on bare hardware
Detected CPU family 6 model 62
------------[ cut here ]------------
WARNING: at kernel/rh_taint.c:13 mark_hardware_unsupported+0x39/0x40() (Not tainted)
Hardware name: PRIMERGY RX300 S8
Your hardware is unsupported.  Please do not report bugs, panics, oopses, etc., on this hardware.
 [<ffffffff8106b747>] ? warn_slowpath_common+0x87/0xc0
 [<ffffffff8106b7df>] ? warn_slowpath_fmt_taint+0x3f/0x50
 [<ffffffff8109a869>] ? mark_hardware_unsupported+0x39/0x40
Trying to unpack rootfs image as initramfs...
Freeing initrd memory: 29766k freed
DMAR: Unsupported device scope

Note: you can also use this command: cat /tmp/syslog | grep -i unsupported -B2

This message occured when kickstarting a RHEL 6.3 operating system. I needed to provide another "vmlinuz" and "initrd.img" for kickstarting the machine.
In case of kickstarting RHEL 6.3, I simply used the vmlinuz and initrd.img from RHEL 6.4.

Description: (my guess...)
I think the first 2 lines will tell you what went wrong during the start of the initial RAM-FS... In my case the RX300 S8 machine from Fujitsu comes with a new CPU type. So the kernel detects "CPU family 6 model 62", but the last supported model type is "CPU family 6 model 59.

...that's just my guess... Can someone help me out with this issue?

Greetings from Germany,

Found another article related to the issue: