Windows NT Boot Process
On Intel-based computers, the system BIOS controls the initial operating
system boot process. After the initial Power On Self Test (POST) when
hardware components are initialized, the system BIOS identifies the boot
device. Typically, this is a floppy disk or a hard disk. In the case of
the hard disk, the BIOS reads the first physical sector on the disk,
called the Master Boot Sector, and loads an image of it into memory. The
BIOS then transfers execution to that image of the Master Boot Sector.
The Master Boot Record contains the partition table and a small amount
of executable code. The executable code examines the partition table and
identifies the active (or bootable) partition. The Master Boot Record
then finds the active partition's starting location on the disk and
loads an image of its first sector, called the Boot Sector, into memory.
The Master Boot Record then transfers execution to that Boot Sector image.
Whereas the Master Boot Record is generally operating system
independent, the Boot Sector of the active partition is dependent on
both the operating system and the file system. In the case of Windows NT
and Windows NT Advanced Server, the Boot Sector is responsible for
locating the executable file, NTLDR, which continues the boot process.
The only disk services available to the Boot Sector code at this stage
of system boot up are provided by the BIOS INT 13 interface. The Boot
Sector code must be able to find NTLDR and file system data structures
such as the root directory, the File Allocation Table (FAT) in the case
of an MS-DOS FAT volume or the Master File Table in the case of an NTFS
volume. These must be present within the area of the disk addressable by
the 24-bit side, cylinder, sector structure used by the BIOS INT 13
interface and the partition table. This limits the size of the system
partition to 7.8 gigabytes regardless of which file system is used.
[end quote]
Windows NT Boot Process and Hard Disk Constraints
http://support.microsoft.com/kb/114841
John
wombat52002@yahoo.co.uk wrote:
> I have a legacy server with NT 4.0 server. I have ghosted back up
> drives around 80 GB IDE/ATA and they have been fine. I recently
> bought some 160 GB IDE and they ghost but they will not boot. Should
> I stick to buying 40, 60 or 80 GB IDE's to ghost. I can still find
> new drives in a box in 40-80 GB range.
>
> Is there something in NT Server 4.0 that cannot handle drives over 80
> GB? I will be moving to VmWare soon. Thanks.
>