Dual Boot / Alternate Boot Questions

G

Gary Brown

Hi,

I will install a second copy of XP on a separate hard disk.
It would run either as a dual boot or with either disk
disconnected. Normally, it would be dual boot. But in case
of disk failure the alternate installation will boot. Is this possible?
Will there be problem getting either OS to boot as "C:"?

I have run triple boot in the past (98/NT4/2003 in separate
partitions) but all on the same disk.

Thanks,
Gary
 
R

Riyazuddin Sk

--
Hi


Gary Brown said:
Hi,

I will install a second copy of XP on a separate hard disk.
It would run either as a dual boot or with either disk
disconnected. Normally, it would be dual boot. But in case
of disk failure the alternate installation will boot. Is this possible?
Will there be problem getting either OS to boot as "C:"?

I have run triple boot in the past (98/NT4/2003 in separate
partitions) but all on the same disk.

Thanks,
Gary

If you remove first disk (first winxp installed) then there will be trouble.

if you remove second disk(second winxp installed) then there will be no
problem except you can't boot second winxp(second disk).

because boot loader files are stored on first winxp drive(first drive).
 
P

Pegasus \(MVP\)

Gary Brown said:
Hi,

I will install a second copy of XP on a separate hard disk.
It would run either as a dual boot or with either disk
disconnected. Normally, it would be dual boot. But in case
of disk failure the alternate installation will boot. Is this possible?
Will there be problem getting either OS to boot as "C:"?

I have run triple boot in the past (98/NT4/2003 in separate
partitions) but all on the same disk.

Thanks,
Gary

Here is how you can do it, using XOSL. Similar solutions may be possible
with other boot managers.
- Connect Disk A only, then install XOSL and an OS.
- Connect Disk B only, then install XOSL and an OS.
- Connect Disk A as a primary master, Disk B as a slave.
- Add the OS on Disk B to the XOSL menu.
- Hide the two OSs from each other.
- Connect Disk B as a primary master, Disk A as a slave.
- Add the OS on Disk A to the XOSL menu.
- Hide the two OSs from each other.
In every case the OS will boot from drive C:. The other OS will be
invisible.
 
T

Timothy Daniels

Gary Brown said:
I will install a second copy of XP on a separate hard disk.
It would run either as a dual boot or with either disk
disconnected. Normally, it would be dual boot. But in case
of disk failure the alternate installation will boot. Is this possible?
Will there be problem getting either OS to boot as "C:"?

I have run triple boot in the past (98/NT4/2003 in separate
partitions) but all on the same disk.

Thanks,
Gary

Piece of cake with Microsoft's own boot.ini boot menu.
There really is no reason to have either OS call its own
partition "C:" as long as each has no shortcuts that point
to other partitions. But if that's what you want, just install
each OS separately to its own hard disk (i.e. with the other
hard disk disconnected). If there are no other OSes on the
disk, the installer will tell the installed OS that its partition is
to be called "C:" - and that's what it will do.

Then, in each OS, add a second boot option to the boot
menu file, which is /boot.ini . (You may have to allow System
files to be unhidden in order to see boot.ini by clicking Show
Hidden Files and Folders in Tools/Folder Options/View tab.)
There will be an entry line under "[operating systems]" that has
rdisk() and partition() components. In rdisk(x), the argument
"x" stands for the boot priority of the hard disk - "0" being the
highest priority, and values range up to "3". In some BIOSes,
the user can set the boot priority of all the hard disks in the system
in arbitray order. In other BIOSes, you "enable" one hard disk
as having the highest priority. In partition(y), "y" stands for the
no. of the partition that contains the OS, starting with "1".
Partitions are numbered starting with the Primary partitions,
and then going to the logical drives in the Extended partition.
(Yes, you can boot an OS that resides on a logical drive in an
Extended partition.) The installer should set the Primary
partition that contains the boot files (ntldr, boot.ini, and
NTdetect.com) to "active". Normally, that partition is the
same as that which contains the OS, but it doesn't have to be.
It wouldn't hurt to use Disk Management to check that the
partition is, indeed, set to "active". If not, set it so.

Since each OS had been installed on a sole hard disk, its
boot.ini file will have "rdisk(0)" in its operating system entry
line. If you had installed each OS in the 1st partition of its hard
disk, both boot.ini files will have "partition(1)" in the entry line.
To make each OS offer the other OS as a boot option in the
boot menu, just add a 2nd line under "[operating systems]"
that has "rdisk(1)" instead of "rdisk(0)". Then at boot time,
regardless which hard disk has boot priority, you can always
select the OS on the local hard disk or the other hard disk.
If one hard disk's MBR gets corrupted, the other hard disk
will be selected (theoretically), and its OS will be booted
automatically because its OS will be the OS indicated in the
"default=" line.

Then you will have several ways to dual-boot. You can
set the boot priority in the BIOS, or you can choose the OS
from the boot menu, or you can swap hard disks. Simple,
yes? And it's all done with Microsoft's own boot software.

BTW, thanks for spelling "separate" correctly. Many
posters spell it "seperate".

*TimDaniels*
 
T

Timothy Daniels

David said:
"Timothy Daniels" typed furiously:
Gary Brown said:
I will install a second copy of XP on a separate hard disk.
It would run either as a dual boot or with either disk
disconnected. Normally, it would be dual boot. But in case
of disk failure the alternate installation will boot. Is this possible?
Will there be problem getting either OS to boot as "C:"?

I have run triple boot in the past (98/NT4/2003 in separate
partitions) but all on the same disk.

Thanks,
Gary

Piece of cake with Microsoft's own boot.ini boot menu.
There really is no reason to have either OS call its own
partition "C:" as long as each has no shortcuts that point
to other partitions. But if that's what you want, just install
each OS separately to its own hard disk (i.e. with the other
hard disk disconnected). If there are no other OSes on the
disk, the installer will tell the installed OS that its partition is
to be called "C:" - and that's what it will do.

Then, in each OS, add a second boot option to the boot
menu file, which is /boot.ini . (You may have to allow System
files to be unhidden in order to see boot.ini by clicking Show
Hidden Files and Folders in Tools/Folder Options/View tab.)
There will be an entry line under "[operating systems]" that has
rdisk() and partition() components. In rdisk(x), the argument
"x" stands for the boot priority of the hard disk - "0" being the
highest priority, and values range up to "3". In some BIOSes,
the user can set the boot priority of all the hard disks in the system
in arbitray order. In other BIOSes, you "enable" one hard disk
as having the highest priority. In partition(y), "y" stands for the
no. of the partition that contains the OS, starting with "1".
Partitions are numbered starting with the Primary partitions,
and then going to the logical drives in the Extended partition.


Note: there are four primary partitions allowed. The extended
partition is a primary partition. The first logical drive in the
extended partition will be numbered 5.
[...]


The Extended Partition differs considerably from a Primary
partition, and the volume numbering you present (with a gap for
the Extended Partition itself and "5" signifying the 1st logical drive)
would only be true if:
1) The OS were Unix/Linux/Solaris/etc, AND
2) There were 3 primary partitions in addition
to the 1 Extended partition

BUT... we're talking about WinXP (and NT and 2K) here.
In those (and probably previous) Windows OSes, there is
no gap in numbering between the highest numbered Primary
partition and the first logical drive within an Extended
partition. Here is an example of volumes in their physical
order on a hard disk and the corresponding entry in the
boot.ini menu file:

Primary partition 1 <--partition(1)
Primary partition 2 <--partition(2)
Extended partition, 1st logical drive <--partition(4)
Primary partition 3 <--partition(3)

I have actually just tested this to confirm it. I put 4 clone
copies of my WinXP OS on a 2nd hard disk in my
desktop system in the physical order given above,
identified eash OS by putting a folder on the Desktop that
indicated the volume's identity, expanded each OS's
boot.ini file to include 4 optional "partition()" selections, set
the 2nd partition "active", disconnected the 1st hard drive,
and started booting. The OSes that booted are indicated
by the above table.

*TimDaniels*
 
J

John John (MVP)

David said:
Note: there are four primary partitions allowed. The extended
partition is a primary partition. The first logical drive in the
extended partition will be numbered 5.

Timothy said:
The Extended Partition differs considerably from a Primary
partition, and the volume numbering you present (with a gap for
the Extended Partition itself and "5" signifying the 1st logical drive)
would only be true if:
1) The OS were Unix/Linux/Solaris/etc, AND
2) There were 3 primary partitions in addition
to the 1 Extended partition

BUT... we're talking about WinXP (and NT and 2K) here.
In those (and probably previous) Windows OSes, there is
no gap in numbering between the highest numbered Primary
partition and the first logical drive within an Extended
partition. Here is an example of volumes in their physical
order on a hard disk and the corresponding entry in the
boot.ini menu file:

Primary partition 1 <--partition(1)
Primary partition 2 <--partition(2)
Extended partition, 1st logical drive <--partition(4)
Primary partition 3 <--partition(3)

I have actually just tested this to confirm it. I put 4 clone
copies of my WinXP OS on a 2nd hard disk in my
desktop system in the physical order given above,
identified eash OS by putting a folder on the Desktop that
indicated the volume's identity, expanded each OS's
boot.ini file to include 4 optional "partition()" selections, set
the 2nd partition "active", disconnected the 1st hard drive,
and started booting. The OSes that booted are indicated
by the above table.
Read your description above and my description. They are both correct.
You are allowed to have up to four primary partitions which are
numbered 1 to 4. The Extended partition is one of those primary
partitions and it may be numbered from 1 to 4 depending on where its
record is in the partition table contained in the Master Boot Record.
(MBR) You could have primary partitions numbered 1 and 4 with no 2 or
3.

The first logical drive in an extended partition is always partition 5
whether there are one, two, three or four primary partitions.

I'm afraid that is incorrect, David. The primary partitions will
receive numbers first and then the first logical drive inside the
extended partition will be given the next available number. If you have
one primary partition and one logical drive inside an extended partition
the logical drive will be partition 2. If you have three primary
partitions and one extended partition with logical drives the first
logical drive will be partition 4.

There is a limit on the number of logical drives available in an
extended partition but I'm not sure whether it is 16, 24 or 32. My
memory is failing due to underuse.

With DOS/W9x it's limited by the available letters, 26 letters, A&B
reserved for floppy drives and C reserved for the active partition, that
leaves 23 letters for logical drives. With Windows XP and the ability
to mount drives to NTFS folders the number of logical drives is unlimited.

John
 

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