Disabling tboot in RHEL6.4+
Environment
- Red Hat Enterprise Linux 6.4 and later
- tboot
Issue
- How can one disable/completely remove
tboot
safely from Red Hat Enterprise Linux 6? - How to make sure that it should not get installed by default in Installation using Kickstart file?
Resolution
-
To avoid installation and configuration of
tboot
in the Red Hat Enterprise Linux 6 machine directly, one can use the following%packages
section.%packages @Base --optional -tboot <extra packages as administrator wants to install>
Safely removing tboot
after installation
-
Using
grubby
, add the existingkernel
# ARGS=$(grep "^[[:space:]]*module /vmlinuz-$(uname -r)" /boot/grub/grub.conf | sed -e 's/^.*x86_64 //' | head -n 1) # grubby --add-kernel=/boot/vmlinuz-$(uname -r) --args="${ARGS}" --initrd=/boot/initramfs-$(uname -r).img --make-default --title "Red Hat Enterprise Linux without tboot ($(uname -r))"
-
Edit
/boot/grub/grub.conf
to add the correspondingroot
directive to the new menu entry created previously# grep -v ^# /boot/grub/grub.conf default=0 timeout=5 serial --unit=0 --speed=115200 terminal --timeout=5 serial console title Red Hat Enterprise Linux without tboot (2.6.32-358.el6.x86_64) kernel /vmlinuz-2.6.32-358.el6.x86_64 ro root=/dev/mapper/vg00-root intel_iommu=on rd_NO_LUKS KEYBOARDTYPE=pc KEYTABLE=us rd_LVM_LV=vg00/swap LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 rd_LVM_LV=vg00/root crashkernel=auto crashkernel=auto console=ttyS0,115200 rd_NO_DM initrd /initramfs-2.6.32-358.el6.x86_64.img title Red Hat Enterprise Linux (2.6.32-358.el6.x86_64) root (hd0,0) kernel /tboot.gz logging=vga,serial,memory module /vmlinuz-2.6.32-358.el6.x86_64 ro root=/dev/mapper/vg00-root intel_iommu=on rd_NO_LUKS KEYBOARDTYPE=pc KEYTABLE=us rd_LVM_LV=vg00/swap LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 rd_LVM_LV=vg00/root crashkernel=auto crashkernel=auto console=ttyS0,115200 rd_NO_DM module /initramfs-2.6.32-358.el6.x86_64.img
Here above, the
Red Hat Enterprise Linux without tboot
entry is missingroot (hd0,0)
, this needs to be added to the entry. -
Remove the
tboot kernel
# grubby --remove-kernel=/boot/tboot.gz # grep -v ^# /boot/grub/grub.conf default=0 timeout=5 serial --unit=0 --speed=115200 terminal --timeout=5 serial console title Red Hat Enterprise Linux without tboot (2.6.32-358.el6.x86_64) root (hd0,0) kernel /vmlinuz-2.6.32-358.el6.x86_64 ro root=/dev/mapper/vg00-root intel_iommu=on rd_NO_LUKS KEYBOARDTYPE=pc KEYTABLE=us rd_LVM_LV=vg00/swap LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 rd_LVM_LV=vg00/root crashkernel=auto crashkernel=auto console=ttyS0,115200 rd_NO_DM initrd /initramfs-2.6.32-358.el6.x86_64.img
-
Now one can remove
tboot
, as it's not in use bygrub
.# yum -y erase tboot
-
Also make sure to have the contents of the file
/etc/sysconfig/kernel
are as follows. If not, simply overwrite it with the following contents# UPDATEDEFAULT specifies if new-kernel-pkg should make # new kernels the default UPDATEDEFAULT=yes # DEFAULTKERNEL specifies the default kernel package type DEFAULTKERNEL=kernel
Root Cause
- Using
--optional
with a@Base
instructanaconda
to install all Optional packages within that group, which includestboot
.
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