minimal "System Partition"?

[Timothy Daniels]

What is the minimal file set that would form what Microsoft calls
the "System" partition (i.e. the Primary partition marked "active"
which can boot load XP from another partition)? I know that
ntldr, boot.ini, and ntdetect.com are needed. But what else?
The swap file? Anything else outside the WINDOWS folder?
I'm considering using a single such partition to load multiple
instances of XP, each residing in a logical drive within a very
large Extended partition.

*TimDaniels*

 

[Juan Perez]

Hi Timothy:

The minimum system requirement for windows XP is 1.5 fo free space. The
partition size depends on how many windows components you install. If you
make a minimun install and you delete the temporal files that you use, in a
windows update, you may find that 5Gb could be enought. But keep in mind
that it will get cramped, in you browse and work with it. Also If you try to
install a Service Pack, it might have not enought space to do it.

Un Saludo
Juan Perez

 

[John John (MVP)]

Seldom required nowadays but SCSI controllers without a SCSI BIOS need
the SSCI driver (NTBOOTDD.SYS) on the system drive. The paging file can
be moved to another partition but for a debug file it is usually best to
keep a minimum pagefile of 126MB on the system drive.

John

 

[Timothy Daniels]

The size of the partition is not my concern. I'm trying to find out what
*files* are needed to make a system partition - that is, a Primary partition
that can be used to load Windows OSes from *other* partitions. I would
like to put these files into one very small Primary partition, and then use the
boot menu/loader in that Primary partition to load selected OSes from
multiple OSes stored in an Extended partition. In Microsoft terminology,
the small Primary partition would act as the "System Partition", and the
partitions in which the OSes reside would be the "Boot Partitions".

*TimDaniels*

"Juan Perez" answered:

 

[AJR]

Regarding "...residing in a logical drive ..." - no-can-do.

A logical drive cannot be designated active/primary - as requirement for OSs

 

[John John (MVP)]

No, not at all. The System Partition *must* be a primary active
partition but the Boot volume can be a logical drive inside an extended
partition.

John

 

[michael]

What is the minimal file set that would form what Microsoft calls
the "System" partition (i.e. the Primary partition marked "active"
which can boot load XP from another partition)? I know that
ntldr, boot.ini, and ntdetect.com are needed. But what else?
The swap file? Anything else outside the WINDOWS folder?
I'm considering using a single such partition to load multiple
instances of XP, each residing in a logical drive within a very
large Extended partition.

*TimDaniels*

boot partition (usually C:, 1MB is enough)

boot.ini
ntldr
ntdetect.com

system partition (varies from place to place):

Documents and Settings
Program Files
Program Files (x86)
WINDOWS

 

[John John (MVP)]

boot partition (usually C:, 1MB is enough)

boot.ini
ntldr
ntdetect.com

system partition (varies from place to place):

Documents and Settings
Program Files
Program Files (x86)
WINDOWS

You got it upside down.

The Microsoft nomenclature defines the following:

*Boot Partition*
The boot partition contains the Windows operating system and its support
files. By default, the Windows operating system files are in the WINDOWS
folder, and the supporting files are in the WINDOWS\System32 folder.
The boot partition can be, but does not have to be, the same as the
system partition. There will be one, and only one, system partition, but
there will be one boot partition for each operating system in a
multi-boot system.

Note On dynamic disks, this is known as the boot volume.

*System Partition*
The system partition refers to the disk volume that contains the
hardware-specific files that are needed to start Windows, such as Ntldr,
Boot.ini, and Ntdetect.com. The system partition can be, but does not
have to be, the same volume as the boot partition.

Note On dynamic disks, this is known as the system volume.

John

 

[Timothy Daniels]

You got it upside down.

The Microsoft nomenclature defines the following:

*Boot Partition*
The boot partition contains the Windows operating system and its support
files. By default, the Windows operating system files are in the WINDOWS
folder, and the supporting files are in the WINDOWS\System32 folder.
The boot partition can be, but does not have to be, the same as the
system partition. There will be one, and only one, system partition, but
there will be one boot partition for each operating system in a
multi-boot system.

Note On dynamic disks, this is known as the boot volume.

*System Partition*
The system partition refers to the disk volume that contains the
hardware-specific files that are needed to start Windows, such as Ntldr,
Boot.ini, and Ntdetect.com. The system partition can be, but does not
have to be, the same volume as the boot partition.

Note On dynamic disks, this is known as the system volume.

John

Right! And can a System Partition consisting of only those 3 files
that were mentioned - ntldr, boot.ini, and ntdetect.com - succeed in
loading and running an OS residing in another partition?

And what does the Boot Partition need besides the WINDOWS,
Program Files, and Documents and Settings folders? Pagefile.sys?
Install.dat? IO.SYS? CONFIG.SYS? AUTOEXEC.BAT?

*TimDaniels*

 

[John John (MVP)]

Right! And can a System Partition consisting of only those 3 files
that were mentioned - ntldr, boot.ini, and ntdetect.com - succeed in
loading and running an OS residing in another partition?

Yes, if it's an NT type operating system, (excluding Vista and Server
2008, which do not use ntldr at all). For Windows 9x/MS-DOS type
operating systems ntldr needs a copy of the boot sector (bootsect.dos).

And what does the Boot Partition need besides the WINDOWS,
Program Files, and Documents and Settings folders? Pagefile.sys?
Install.dat? IO.SYS? CONFIG.SYS? AUTOEXEC.BAT?

Speaking of Windows NT/2000/XP it only needs the Windows folder and
support files (the System32 folder). You can put those other files that
you mention anywhere else on the disk. I'm not sure what Install.dat is
but it isn't needed by NT type installations. On NT type installations
IO.SYS, CONFIG.SYS, and AUTOEXEC.BAT are not needed, they are there for
compatibility purposes with legacy applications only. The Autoexec.bat
file can be parsed for environment variables and the variables can be
included in the current user environment when Windows is started, this
behaviour can be changed via a registry edit.

John

 

[Timothy Daniels]

"John John (MVP)" answered:

Yes, if it's an NT type operating system, (excluding Vista and Server 2008,
which do not use ntldr at all). For Windows 9x/MS-DOS type operating systems
ntldr needs a copy of the boot sector (bootsect.dos).



Speaking of Windows NT/2000/XP it only needs the Windows folder
and support files (the System32 folder). You can put those other files
that you mention anywhere else on the disk. I'm not sure what
Install.dat is but it isn't needed by NT type installations. On NT type
installations IO.SYS, CONFIG.SYS, and AUTOEXEC.BAT are
not needed, they are there for compatibility purposes with legacy
applications only. The Autoexec.bat file can be parsed for
environment variables and the variables can be included in the
current user environment when Windows is started, this behaviour
can be changed via a registry edit.

John

Thanks for the reply. It sounds like this would work, then:

Create an NTFS Primary partition of about 400KB for the System Partition.
Install XP to another NTFS partition of, say 30GB for XP's Boot Partition.
Copy ntldr, boot.ini, and ntdetect.com from the Boot Partition to the
400KB System Partition.
Mark the 400KB System Partition "active" (assuming one hard drive.)

At startup, ntldr in the 400KB System Partition would get control,
and the entries in the boot.ini file would direct ntldr to load the XP in
the 30GB Boot Partition. Correct?

Corollary: I know that I can put a clone of XP into a logical drive
in an Extended partition and that I can boot it from another XP installation
that acts as the System Partition. The only "trick" is to use the correct
partition number in the "partition()" parameter of the boot.ini entry. But
does one have to go through the procedure of installing to a Primary
partition first and then cloning that Primary partition to a logical drive?
IOW, can one install XP directly to a logical drive provided that the
logical drive doesn't have to be a System Partition?

*TimDaniels*

 

[John John (MVP)]

"John John (MVP)" answered:




Thanks for the reply. It sounds like this would work, then:

Create an NTFS Primary partition of about 400KB for the System Partition.
Install XP to another NTFS partition of, say 30GB for XP's Boot Partition.
Copy ntldr, boot.ini, and ntdetect.com from the Boot Partition to the
400KB System Partition.
Mark the 400KB System Partition "active" (assuming one hard drive.)

You won't be able to create such a small (400KB) partition, 8MB is about
as small a partition that can be formatted to NTFS. Create the small
NTFS partition and mark it active right after you format it. Then
create other partition(s) for the operating system(s) and proceed to
install Windows on the desired partition. The Windows setup program
will automatically place the system files (Boot.ini, NTDETECT.COM &
ntldr) on the 8MB active partition, there is no need to make 2 primary
partitions (the system files cannot be placed on a logical drive) and to
copy the file over and toggle the active flag after the installation.

At startup, ntldr in the 400KB System Partition would get control,
and the entries in the boot.ini file would direct ntldr to load the XP in
the 30GB Boot Partition. Correct?
Yes.


Corollary: I know that I can put a clone of XP into a logical drive
in an Extended partition and that I can boot it from another XP installation
that acts as the System Partition. The only "trick" is to use the correct
partition number in the "partition()" parameter of the boot.ini entry. But
does one have to go through the procedure of installing to a Primary
partition first and then cloning that Primary partition to a logical drive?
IOW, can one install XP directly to a logical drive provided that the
logical drive doesn't have to be a System Partition?

You can install directly to a logical drive and you can then clone the
installation to any other drive. There is no requirements that Windows
XP be installed to a primary partition, the only requirement is that
there be a System Partition and that it (the System Partition) be an
active primary partition. The boot partition can be, but does not have
to be, the same as the system partition. A logical drive can never be a
System Partition for the simple reason that a logical drive cannot be
made "Active".

John

 

[Timothy Daniels]

"John John (MVP)" explained:

You won't be able to create such a small (400KB) partition, 8MB is about
as small a partition that can be formatted to NTFS. Create the small
NTFS partition and mark it active right after you format it. Then
create other partition(s) for the operating system(s) and proceed to
install Windows on the desired partition. The Windows setup program
will automatically place the system files (Boot.ini, NTDETECT.COM &
ntldr) on the 8MB active partition, there is no need to make 2 primary
partitions (the system files cannot be placed on a logical drive) and to
copy the file over and toggle the active flag after the installation.



You can install directly to a logical drive and you can then clone the
installation to any other drive. There is no requirements that Windows XP be
installed to a primary partition, the only requirement is that there be a
System Partition and that it (the System Partition) be an active primary
partition. The boot partition can be, but does not have to be, the same as
the system partition. A logical drive can never be a System Partition for the
simple reason that a logical drive cannot be made "Active".

John

Thanks for illucidating, John. (And thanks for continuing with the
bottom-posting.) That clears up at least a couple mysteries for me.
I think it would be valuable to anyone multi-booting several Windows
OSes off the same hard drive.

*TimDaniels*

 

[John John (MVP)]

"John John (MVP)" explained:



Thanks for illucidating, John. (And thanks for continuing with the
bottom-posting.) That clears up at least a couple mysteries for me.
I think it would be valuable to anyone multi-booting several Windows
OSes off the same hard drive.

You're welcome, Tim.

Also keep this in mind: To successfully boot an NT type operating
system the system partition must have an NT boot sector. The boot
sector is written to the partition when the partition is formatted. If
you create and format partitions with the Windows XP setup CD, or from a
Windows NT/2000/XP installation an NT boot sector will be written to the
partitions. If you format with third party utilities or with a W98
setup diskette (like many form the W98 crowd often do) the partition
will not have an NT boot sector and it will fail to boot NT
installations. When the Windows XP setup program does the installation
it will write a proper boot sector to the system partition (fixboot),
but if you toy with the system partition with other formating utilities
after the installation the boot sector will be overwritten and you will
have to use the Recovery Console's Fixboot command to repair the boot
sector. This overwriting of the boot sector is something that is
sometimes seen when folks do disk work and use non NT formating
utilities in a non NT environment.

John

 

[Timothy Daniels]

"John John (MVP)" added:

You're welcome, Tim.

Also keep this in mind: To successfully boot an NT type operating system, the
system partition must have an NT boot sector. The boot sector is written to
the partition when the partition is formatted. If you create and format
partitions with the Windows XP setup CD
or from a Windows NT/2000/XP installation, an NT boot sector
will be written to the partitions. If you format with third party utilities
or with a W98 setup diskette (like many form the W98 crowd often
do), the partition will not have an NT boot sector and it will fail to
boot NT installations. When the Windows XP setup program does
the installation it will write a proper boot sector to the system partition
(fixboot), but if you toy with the system partition with other formating
utilities after the installation the boot sector will be overwritten and
you will have to use the Recovery Console's Fixboot command to
repair the boot sector. This overwriting of the boot sector is
something that is sometimes seen when folks do disk work and use
non NT formating utilities in a non NT environment.

John

Thanks again, John. I have wondered when and by what software
the boot sector was written. That also clears up a recent mystery with
an Ubuntu installation - the installer kept insisting that it do the formatting
even though the Ubuntu partitions had already been formatted.

*TimDaniels*