Chapter 12. Installation and Booting

Non-volatile memory NVM Express (NVMe) devices are not supported by the GRUB boot loader in Red Hat Enterprise Linux 6, and therefore the boot loader can't be installed on these devices.

To work around the problem, you can:

(BZ#1227194)

When the GRUB boot loader is updated using yum or rpm (for example, rpm -Uvh grub), and the update process succeeds, then the grub-install command is not being run automatically due to technical limitations of GRUB. The updated package is downloaded and installed, but the new version of the boot loader provided by that package is not automatically applied to the system. Instead, the old version is used even after the package update, and therefore any fixes provided in the update are not applied to the system.

To work around this problem, run the grub-install command manually using a command line with root privileges every time an update to the grub package is installed. (BZ#1573121)

In UEFI mode, GRUB Legacy supports only MD5-encrypted passwords and does not support SHA256 and SHA512-encrypted passwords. Consequently, the operating system becomes unresponsive at boot time, when using SHA256 and SHA512-encrypted passwords in UEFI mode.

To work around this problem, you can: