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48-Bit LBA Support for ATAPI Disk Drives in
Windows 2000
This article was previously published under Q305098
SYMPTOMS
Windows 2000 Service Pack 2 (SP2) and earlier versions of
Windows 2000 do not support 48-bit Logical Block Addressing (LBA) as defined
in the ATA/ATAPI 6.0 specification.
RESOLUTION
To resolve this problem, obtain the latest service pack for
Windows 2000. For additional information, click the following article number
to view the article in the Microsoft Knowledge Base:
260910 How to Obtain the Latest Windows
2000 Service Pack
The English-language version of this fix should have the
following file attributes or later:
Date Time Version Size File name
--------------------------------------------------------
10/19/2001 01:42 PM 5.0.2195.4529 86,768 Atapi.sys
04/19/2002 05:43 PM 214,938 Update.inf
The following conditions are necessary for the correct
functioning of 48-bit LBA ATAPI support:
·
A computer with a 48-bit LBA-compatible Basic
Input/Output System (BIOS) installed.
·
A computer with a hard disk that has a
capacity of greater than 137 gigabytes (GB).
·
You must enable the support in the Windows
registry by adding or changing the EnableBigLba registry value to 1
in the following registry subkey:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\atapi\Parameters
To enable 48-bit LBA large-disk support in the registry:
Start Registry Editor (Regedt32.exe).
Locate and then click the following key in the registry:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Atapi\Parameters
On the Edit menu, click Add Value, and then
add the following registry value:
Value name: EnableBigLba
Data type: REG_DWORD
Value data: 0x1
Quit Registry Editor.
NOTE: If you enable 48-bit
LBA ATAPI support by editing the preceding registry key, but your system does
not meet the minimum requirements, you may observe the following behaviors:
·
Operating systems that do not have 48-bit LBA
support enabled by default (such as Microsoft Windows 98, Microsoft Windows
Millennium Edition (Me), or Windows 2000) that are installed on a partition
that spans beyond the 28-bit LBA boundary (137GB) will experience data
corruption or data loss.
·
The installation of operating systems that do
not have 48-bit LBA support enabled by default (such as Windows 98, Windows
Me, or Windows 2000) on a partition that is beyond the 28-bit LBA boundary
(137 GB) is unsuccessful and leaves behind a temporary installation folder.
·
If you install hotfixes that enable 48-bit
LBA before you install Windows 2000 Service Pack 3 (SP3), the appropriate
registry key will be automatically created during the installation of SP3 to
preserve the data integrity of the hard disk.
·
After you enable 48-bit LBA support by adding
the appropriate registry key, data corruption may occur if you remove the
registry key or if you remove (uninstall) SP3 for Windows 2000.
·
If you install a copy of Windows 2000 that
includes SP3 (SP3 integrated) on a large hard disk that has already been
preformatted by using a 48-bit LBA-enabled operating system, the ATAPI
subsystem may report hard-disk space greater than that which is addressable
without the 48-bit LBA support (larger than approximately 137 GB) during the
text-mode portion of Setup. In this case, the hard disk's partition table
information has already been created. To fix the incorrect disk information,
delete the partition by using either a disk partitioning utility or by
deleting and then re-creating the partition during the text-mode portion of
Setup. After you create the new partition, quit Setup by pressing F3, and then
restart the Windows installation process. The ATAPI subsystem now correctly
shows approximately 137 GB of hard disk space.
·
The EnableBigLba registry value is
disabled:
If you have a 48-bit compatible BIOS that can support a hard disk that has a
capacity of more than 137 GB, only the first 137 GB of the hard disk is
addressable. The remainder of the hard disk is not used.
·
The operating system must be installed on the
first partition that is smaller or equal to 137 GB when the EnableBigLba
registry value is enabled but when you do not have a 48-bit LBA compatible
BIOS.
If you enable the 48-bit LBA ATAPI support by editing the registry setting,
but you lack both a 48-bit LBA compatible BIOS and a hard disk that has a
capacity of more than 137 GB, the hard disk continues to function as a
standard hard disk with an addressable limit of 137 GB.
·
The operating system must be installed on the
first partition that is less than or equal to 137 GB and the rest of the hard
disk divided into one or more remaining partitions when the EnableBigLba
registry value is enabled on a computer without a 48-bit LBA compatible BIOS
that has a hard disk with a capacity of more than 137 GB.
STATUS
Microsoft has confirmed that this is a problem in the
Microsoft products that are listed at the beginning of this article. This
problem was first corrected in Windows 2000 Service Pack 3.Important
Although support for 48-bit LBA is included in Windows 2000 Service Pack 3
(SP3) and later, it is still necessary to create the registry change that is
described in the "Resolution" section of this article.
MORE INFORMATION
For additional information about how to obtain a hotfix for
Windows 2000 Datacenter Server, click the article number below to view the
article in the Microsoft Knowledge Base:
265173 The Datacenter Program and Windows
2000 Datacenter Server Product
For additional information about how to install multiple
hotfixes with only one reboot, click the following article number to view the
article in the Microsoft Knowledge Base:
296861 How to Install Multiple Windows
Updates or Hotfixes with Only One Reboot
For additional information about how to install Windows
2000 and Windows 2000 hotfixes at the same time, click the article number
below to view the article in the Microsoft Knowledge Base:
249149 Installing Microsoft Windows 2000
and Windows 2000 Hotfixes
How
to Enable 48-bit Logical Block Addressing Support for ATAPI Disk Drives in
Windows XP
This article was previously published under Q303013
SUMMARY
This article describes the Windows XP Service Pack 1 (SP1)
48-bit Logical Block Addressing (LBA) support for ATA Packet Interface (ATAPI)
disk drives that can enable the capacity of your hard disk to exceed the
current 137 gigabyte (GB) limit.
Note 48-bit LBA support is not enabled and therefore supported without
Windows XP SP1. Windows XP Media Center Edition and Windows XP Tablet PC
Edition already include SP1.
For additional information about the latest service pack for Windows XP, click
the article number below to view the article in the Microsoft Knowledge Base:
322389 How to Obtain the Latest Windows XP
Service Pack
MORE INFORMATION
Windows XP SP1 includes 48-bit LBA support for ATAPI disk
drives. With this support, you can use hard disks that are larger than the
current 137 GB limit. By default, support is enabled in SP1. To determine if
you are running SP1, right-click My Computer and then click Properties. On the
General tab, Service Pack 1 will be listed under System.
To determine if you have the latest ATAPI driver, verify that the version of
Atapi.sys in your %systemroot%\system32\drivers folder is version
5.1.2600.1135 (or version 5.1.2600.1152 for Windows XP 64-Bit Edition) or
later. To do this, follow these steps:
Click Start, and then click Search (or point to Search and
then click For Files and Folders).
Type
Atapi.sys, and then click Search.
If the Atapi.sys file in your %systemroot%\system32\drivers
folder is not found, change your preferences for the Search Companion to
search system and hidden folders and then repeat step 2. For additional
information about how to search for hidden and system folders, click the
following article number to view the article in the Microsoft Knowledge Base:
302347 HOW TO: Search For Hidden Or System
Files In Windows XP
In your %systemroot%\System32\Drivers folder, Right-click
Atapi.sys, and then click Properties.
On the Version tab, note the file version.
If Atapi.sys is not version 5.1.2600.1135 (or version
5.1.2600.1152 for Windows XP 64-Bit Edition), obtain and install the hotfix
described in Microsoft Knowledge Base article 331958. For additional
information about this hotfix, click the following article number to view the
article in the Microsoft Knowledge Base:
331958 Hard Disk May Become Corrupted When
Entering Standby or Hibernation or When Writing a Memory Dump
By default, the original release of Windows XP Home Edition
and Windows XP Professional do not have 48-bit LBA support enabled.
You must meet the following requirements to use 48-bit LBA ATAPI support:
·
You must have a 48-bit LBA compatible BIOS.
·
You must have a hard disk that has a capacity
that is greater than 137 GB.
·
You must have Windows XP SP1 installed.
For the original release of Windows XP Home Edition or
Windows XP Professional, 48-bit LBA could be enabled for testing purposes by
setting a registry value, named EnableBigLba, to 1 in the
following registry key:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Atapi\Parameters\
Warning Data corruption can
occur you use this registry value to enable 48-bit LBA support in the original
release of Windows XP Home Edition or Windows XP Professional, or if previous
versions of Windows that do not support 48-bit LBA out of the box (for
example, Windows 2000 or earlier) are installed on a disk partition that was
previously created by a 48-bit aware operating system such as Windows XP SP1
that is larger or spans the current addressable limit of 137 GB.
Note: The preceding registry setting is ignored in Windows XP SP1 and
later. If you attempt to enable the 48-bit LBA ATAPI support in the original
release of Windows XP Home Edition or Windows XP Professional by editing the
preceding registry setting and you did not meet the minimum requirements, you
may observe the following behavior:
·
The registry value EnableBigLba is
disabled. If you have a 48-bit compatible BIOS that can support a hard disk
that has a capacity that is greater than 137 GB, only the first 137 GB of
the hard disk are addressable. The rest of the hard disk is not used.
·
The registry value EnableBigLba is
enabled, but you do not have a 48-bit LBA compatible BIOS and the capacity
of the hard disk does not exceed 137 GB:
If you enable the 48-bit LBA ATAPI support by editing the registry setting,
but you lack both a 48-bit LBA compatible BIOS and a hard disk that has a
capacity that is greater than 137 GB, you have not changed the system. The
hard disk continues to function as a standard hard disk.
·
The registry value EnableBigLba is
enabled without a 48-bit LBA compatible BIOS, but you have a hard disk with
a capacity that is larger than 137 GB.
If you enable 48-bit ATAPI support in the registry and you have a hard disk
that has a capacity that is greater than 137 GB, but you do not have a
48-bit LBA compatible BIOS, only the first 137 GB of the hard disk are
addressable.
The remainder of the hard disk is not used.
To enable 48-bit LBA support by means of an unattended
installation with the Microsoft System Preparation (Sysprep) tool:
Copy the following text into Microsoft Windows Notepad and
save the text as the 48bitLba.inf file:
[version]
signature="$CHICAGO$"
SetupClass=BASE
[DefaultInstall]
AddReg=48bitlba.Add.Reg
[48bitlba.Add.Reg]
HKLM,"System\CurrentControlSet\Services\Atapi\Parameters","EnableBigLba",0x10001,1
Create a file named Cmdlines.txt, which includes the following lines:
[Commands]
"rundll32 setupapi,InstallHinfSection DefaultInstall 128 .\48BITLBA.INF"
Locate the Sysprep\I386 folder in the Sysprep image, and then create a $OEM$
subfolder in this folder.
Copy the 48bitlba.inf and Cmdlines.txt files into the Sysprep\I386\$OEM$
folder.
In your Sysprep.inf file, add a key named InstallFilesPath to the
[Unattended] section. This key must have the following value:
InstallFilesPath = "C:\sysprep\i386"
To add the preceding settings to the Images folder, which had been created
with the Riprep.exe program:
On the remote installation server that contains the Riprep image, create a
Sysprep\I386\$OEM$ folder in the following folder:
RemoteInstall\Setup\Language\Images\Riprep_dir_name\I386\Mirror1\UserData
Note The word "Language" in the preceding path reads "English" for the
English language, and "Riprep_dir_name" is the unique name that you selected
for the Riprep image.
Copy the 48bitlba.inf and Cmdlines.txt files into the $OEM$ folder.
Modify the Riprep.sif file in the RemoteInstall\Setup\Language\Images\Riprep_dir_name\I386\Templates\Riprep.sif
folder (and any other template files for this Riprep image that you may have
created), and then add the OemPreinstall and InstallFilesPath values so that
they are set up as:
[Unattended]
OemPreinstall = "Yes"
InstallFilesPath = "C:\sysprep\i386"
Close, and then save the file.
OEMs have the ability to turn this support on by means of the Microsoft
Windows OEM Preinstallation Kit.
For more information, refer to the OEM Preinstallation Kit or the following
Microsoft Web site:
http://www.microsoft.com/oem
The information in this
article applies to:
·
Microsoft Windows XP Tablet PC Edition
·
Microsoft Windows XP Media Center Edition
·
Microsoft Windows XP Home Edition SP1
·
Microsoft Windows XP Professional SP1
·
Microsoft Windows XP 64-Bit Edition Version
2002 SP1
Limitations of FAT32 File System
This article was previously published under Q184006
For a Microsoft Windows XP version of this article, see
314463
SUMMARY
This article discusses limitations of the FAT32 file system
with Windows operating systems.
MORE INFORMATION
The following limitations exist using the FAT32 file system
with Windows operating systems:
·
Clusters cannot be 64 kilobytes (KB) or
larger. If clusters were 64 KB or larger, some programs (such as Setup
programs) might calculate disk space incorrectly.
·
A volume must contain at least 65,527
clusters to use the FAT32 file system. You cannot increase the cluster size on
a volume using the FAT32 file system so that it ends up with less than 65,527
clusters.
·
The maximum possible number of clusters on a
volume using the FAT32 file system is 268,435,445. With a maximum of 32 KB per
cluster with space for the file allocation table (FAT), this equates to a
maximum disk size of approximately 8 terabytes (TB).
·
The ScanDisk tool included with Microsoft
Windows 95 and Microsoft Windows 98 is a 16-bit program. Such programs have a
single memory block maximum allocation size of 16 MB less 64 KB. Therefore,
The Windows 95 or Windows 98 ScanDisk tool cannot process volumes using the
FAT32 file system that have a FAT larger than 16 MB less 64 KB in size. A FAT
entry on a volume using the FAT32 file system uses 4 bytes, so ScanDisk cannot
process the FAT on a volume using the FAT32 file system that defines more than
4,177,920 clusters (including the two reserved clusters). Including the FATs
themselves, this works out, at the maximum of 32 KB per cluster, to a volume
size of 127.53 gigabytes (GB).
·
You cannot decrease the cluster size on a
volume using the FAT32 file system so that the FAT ends up larger than 16 MB
less 64 KB in size.
·
You cannot format a volume larger than 32 GB
in size using the FAT32 file system in Windows 2000. The Windows 2000 FastFAT
driver can mount and support volumes larger than 32 GB that use the FAT32 file
system (subject to the other limits), but you cannot create one using the
Format tool. This behavior is by design. If you need to create a volume larger
than 32 GB, use the NTFS file system instead.
NOTE: When attempting to
format a FAT32 partition larger than 32 GB, the format fails near the end of
the process with the following error:
Logical Disk Manager: Volume size too big.
What is the biggest disk NT can use?
John Savill
InstantDoc #13720
John Savill's FAQ for Windows
A. The simple answer to this question is that NT can view a
maximum partition size of 2 terabytes (or 2,199,023,255,552 bytes),
however there are limitations that restrict you well
below this number.
FAT has internal limits of 4 GB due to thefact it uses
16-bit fields to store file sizes, 2^16 is 65,536 with a cluster size
of 64 KB gives us the 4 GB.
HPFS uses 32bit fields and can therefore handle greater
size disks, but the largest single file size is 4GB. HPFS allocates
disk space in 512 byte sectors which can cause problems
in Asian markets where sector sizes are typically 1024 bytes which
means HPFS cannot be used.
NTFS uses 64-bits for all sizes, leading to a max size
of..... 16 exabytes!!! (18,446,744,073,709,551,616 bytes), however NT
could not handle a volume this big.
For IDE drives, the maximum is 136.9 GB, however for a
standard IDE drive this is constrained to 528MB. The new EIDE drives
can access much larger sizes.
It is important to note that the System partition
(holding ntldr, boot.ini, etc.) MUST be entirely within the first 7.8Gb
of any disk (if this is the same as the boot partition
this limit applies) This is due to the BIOS int 13H interface used
by ntldr to bootstrap up to the point where it can drive
the native HDD IDE or SCSI. int 13H presents a 24 bit parameter for
cylinder/head/sector for a drive. If say by
defragmentation the system are moved beyond this point you will not be able to
boot the system.
The 7.8GB limit is only true on an IDE-type drive if the
heads=255 and sectors=63. The real limit is the 1024 cylinder limit.
If, for example, the heads=16 (as some IDE drives insist
on) then the files mentioned must live within the first 504MB. This
whole BIOS/big disk situation is getting worse and worse
recently as manufacturers GHOST images onto 20GB and 30GB
single-partition volumes, and do it on machines without
the BIOS INT13 support for a volume that size.
The boot process starts with your BIOS (Basic
Input/Output System), not Windows NT.
The BIOS locates the beginning of a partition by using
three numbers, the Starting Side (or Head), the Starting Cylinder, and
the Starting Sector.
The end of a partition is identified by three similar
numbers. The Side value is 8 bits with a range from 0 to 255 (256 numbers);
the Cylinder is 10 bits, and can range from 0 to 1023
(1024 numbers); the Sector is 6 bits, and can range from 1 to 63
(63 numbers). (Note that zero is not a valid sector
number.) This means the maximum address on the disk is Side 255, Cylinder
1023, Sector 63. The number of sectors is 256 X 1023 X
63, or almost 16.5 million sectors. Standard sectors are 512 bytes, so
hence the size of 7.87GB in which the system files must
reside in.
B. Windows 2000 has no such limitation. These are limits
imposed by the specific machine BIOS. Newer machines/BIOSes typically
don't have
this limitation.
Link1:
http://www.winnetmag.com
Link2:
http://www.dewassoc.com
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