IBM 88553RX, Installation Manual

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Chapter 1. Technical description
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Currently, only 64-bit operating systems have the ability to read, write, and boot
from GPT disks. 32-bit operating systems do not have built-in support for GPT
disks.
The specification for GPT disk partitioning can be found in Chapter 16 of the
Extensible Firmware Interface (EFI) specification. This document is available at:
http://developer.intel.com/technology/efi/download.htm
1.10.2 EFI System Partition
A special partition on the GPT disk is the
EFI System Partition
(ESP). It contains
the OS loader files of all installed operating systems. These files are stored in the
EFI directory. The ESP may also contain other files necessary to boot the
system, such as drivers. The EFI System Partition is shareable among all
installed operating systems. To support multiple operating system installations,
create multiple data partitions.
An example directory structure for an EFI System Partition present on a hard disk
with Linux and Windows Server 2003 installed is as follows:
\EFI
\Microsoft
\WINNT50
\EFIDrivers
\SuSE
\RedHat
\MSUtils
There can be only one ESP on a single disk. The size of the ESP is determined
using the following algorithm:
ESP = max(100 MB, min(1% of physical disk, 1GB))
In other words, the size of the ESP must be the larger of these two numbers, 100
MB or 1 percent of the physical disk size (up to 1 GB). For example, for an 18 GB
disk, the size of the ESP is 184 MB. The value 1 percent of the physical disk is
calculated at the time that the ESP is created and does not change if the disk is
extended later (for example, via RAID).
Warning: Windows Server 2003 Enterprise and Datacenter Editions require a
Microsoft Reserved Partition (MSR), which must come after the ESP. If
Windows and Linux need to reside on the same machine then Windows must
be installed first.