An updated grub package that fixes three bugs and adds two enhancements is now available for Red Hat Enterprise Linux 6.
The GRUB utility is responsible for booting the operating system kernel.
Due to an error in the underlying source code, previous versions of GRUB may have failed to boot in Unified Extensible Firmware Interface (UEFI) mode. This happened, because GRUB was making UEFI calls without aligning the stack pointer to a 16-byte boundary. With this update, a patch has been applied to correct this error, and GRUB now boots in UEFI mode as expected.
Prior to this update, an attempt to install GRUB on a CCISS device may have caused the grub-install utility to report the following error:
expr: non-numeric argument
When this happened, grub-install failed to install GRUB on this device, but incorrectly reported success and returned a zero exit status. This update applies a patch that ensures that GRUB can now be successfully installed on such devices.
When looking for its configuration file, the previous versions of GRUB did not respect vendor-specific EFI device path. With this update, the underlying source code has been adapted to use the vendor-specific EFI-device path as expected.
Prior to this update, the GRUB boot loader was unable to boot from boot drives that were larger than 2.2 TB. This update adds support for such devices on UEFI systems.
On BIOS-based systems, previous versions of GRUB were only able to boot from first eight disk drives. This update allows GRUB to boot from up to 128 disk drives on these systems.
All users of grub are advised to upgrade to this updated package, which fixes these bugs and adds these enhancements.