36.3.2. Blacklisting a Driver

Boot the system into rescue mode with the command linux rescue rdblacklist=name_of_driver, where name_of_driver is the driver that you need to blacklist. Follow the instructions in Section 36.1.2, “Booting into Rescue Mode” and do not choose to mount the installed system as read only.

Open the /mnt/sysimage/boot/grub/grub.conf file with the vi text editor:

vi /mnt/sysimage/boot/grub/grub.conf

vi /mnt/sysimage/boot/grub/grub.conf

Identify the default kernel used to boot the system. Each kernel is specified in the grub.conf file with a group of lines that begins title. The default kernel is specified by the default parameter near the start of the file. A value of 0 refers to the kernel described in the first group of lines, a value of 1 refers to the kernel described in the second group, and higher values refer to subsequent kernels in turn.

Edit the kernel line of the group to include the option rdblacklist=name_of_driver, where name_of_driver is the driver that you need to blacklist. For example, to blacklist the driver named foobar:

kernel /vmlinuz-2.6.32-71.18-2.el6.i686 ro root=/dev/sda1 rhgb quiet rdblacklist=foobar

kernel /vmlinuz-2.6.32-71.18-2.el6.i686 ro root=/dev/sda1 rhgb quiet rdblacklist=foobar

Save the file and exit vi.

Create a new file under /etc/modprobe.d/ that contains the command blacklist name_of_driver. Give the file a descriptive name that will help you find it in future, and use the filename extension .conf. For example, to continue to blacklist the driver foobar when the root device is mounted, run:

echo "blacklist foobar" >> /mnt/sysimage/etc/modprobe.d/blacklist-foobar.conf

echo "blacklist foobar" >> /mnt/sysimage/etc/modprobe.d/blacklist-foobar.conf

Reboot the system. You no longer need to supply rdblacklist manually as a kernel option until you next update the default kernel. If you update the default kernel before the problem with the driver has been fixed, you must edit grub.conf again to ensure that the faulty driver is not loaded at boot time.