HP ProLiant BL660c ISS Technology Focus, Number 12 - Page 4

To boot an OS on a UEFI-based system, one of the partitions must be a UEFI system partition containing a FAT32 file system and the boot loader executable programs for one or more OSes. The UEFI system firmware loads the GPT partition table, searches for the UEFI system partition, reads the selected boot loader into memory, and then begins executing it. The boot loader understands the file system of the partition containing the rest of the OS and bootstraps the OS. How should you configure high-capacity drives to boot the OS? Microsoft Windows Microsoft Windows supports booting from GPT drives on UEFI-based systems, like HP Integrity servers. Microsoft Windows does not support booting from GPT drives on legacy BIOS-based systems, like ProLiant servers. Microsoft Windows supports booting from MBR drives on legacy BIOSbased systems, like HP ProLiant servers. Because of the MBR partitioning scheme, you must configure the system with an array when using highcapacity drives. Use the Array Configuration Utility to create a logical drive that is less than 2.2 TB for booting the OS, and then partition that logical drive using MBR. Linux Linux supports booting from GPT drives on UEFI-based systems, like HP Integrity servers. The grub2 and syslinux boot loaders support booting from GPT-partitioned drives of any capacity on legacy BIOS-based systems, like ProLiant servers. Ubuntu Server 10 and 11 support grub2. Red Hat Enterprise Linux 6 and SUSE Linux Enterprise Server 11 are still on grub1. If you do not use the grub2 or syslinux boot loader, use the Array Configuration Utility to create a logical drive for booting that is less than 2.2 TB and partition it using MBR. Logical drives used for data may be larger than 2.2 TB and partitioned with GPT. The grub2 boot loader places x86 boot code in LBA 0. LBA 0 contains the hard-coded LBA of a special GPT partition named the "BIOS Boot Partition." The grub2 boot loader loads the VBR from the BIOS Boot Partition, and then begins executing that code. The GUID for the BIOS Boot Partition is the ASCII string "Hah!IdontneedEFI." The BIOS Boot Partition size must be less than 2.2 TB, but it may be located at any LBA. If you move the BIOS Boot Partition, you must also update the LBA embedded in the boot code in LBA 0.