Multi-booting
![](http://upload.wikimedia.org/wikipedia/commons/thumb/c/cf/GRUB_with_ubuntu_and_windows_vista.png/300px-GRUB_with_ubuntu_and_windows_vista.png)
Multi-boot or Multi-booting (usually dual-booting, but many OSes can be booted from the same computer) is the act of installing multiple operating systems on a computer, and being able to choose which one to boot when switching on the computer power. The program which makes multi-booting possible is called a boot loader.
Usage
Multi-booting is useful in many situations, such as those where several pieces of software require different operating systems and cannot be run on a single system. A multi-boot configuration will allow a user to use all of this software on one computer. Another reason for setting up a multi-boot system can be that one wants to investigate or test a new operating system without switching completely. Multi-booting allows one to get to know the new system, configure all applications needed and migrate data before making the final step and removing the old operating system. This is often accomplished by using a boot loader that can boot more than one operating system, such as NTLDR, LILO, or GRUB.
Multi-booting can also aid software developers where multiple operating systems are required for development or testing purposes. Having these systems on one machine can greatly reduce hardware costs. (However hardware costs are counterbalanced by system management costs, and the costs of the unavailability of the software that cannot be run at any given moment. Another solution to these problems is to use virtual machine software to emulate another computer from within the operating system of choice1.)
Technical issues
Compatibility problems may arise with different operating systems: one operating system may not be able to recognize the other operating system's file system and thus may try to format it to its native file system, erasing existing data. This happens more often when the file systems are in separate partitions on one disk than when they are on separate disks.[citation needed] Sometimes an administrator must manually configure one operating system to ignore the other disk or partition in order to allow multiple file systems.
Multi-Booting Windows
Further difficulties can arise when trying to install multiple Windows operating systems in a dual-boot environment, due to the difference between system and boot partitions. When installing another copy of Windows to a secondary partition or disk in the same system where both partitions are visible, the installation procedure will utilize the same boot volume for booting the machine, yet require the OS to continue booting from its own system partition. This creates a problem as the new partition will be dependent on the old partition, and will not be able to boot unless both partitions are properly configured. A simple solution to prevent this problem is to first hide the initial partition using an application such as MBRWizard before attempting the secondary Windows installation. This will eliminate dependencies on other partitions and provide complete autonomy.
It is also advisable that if one wishes to dual-boot Windows, they should partition their drive into as many partitions of any reasonable size, and install each windows in the order it was released, so the newest NTLDR will be installed last, including all previous Windows OS releases.
Apple Boot Camp
Boot Camp allows owners of Intel-based Apple Macintosh computers to install Windows XP and Vista on their Macs. The software comes bundled with Mac OS X 10.5 Leopard and Mac OS X 10.6 Snow Leopard, Apple's latest version of the Operating System included on their computers. Previously the application was available in beta version as a download from Apple's website.
Boot Camp allows non-destructive disk partitioning and resizing of HFS+ filesystems, boot menu options, and an option to burn a CD with necessary device drivers. Since Windows XP is incompatible with Extensible Firmware Interface (the successor to legacy BIOS), the firmware on early Intel Macs need to be updated to support BIOS emulation first. BIOS emulation is achieved with a compatibility support module (CSM). Apple does not support non-Windows partition formats or drivers so therefore configuring other operating systems is not directly possible through Boot Camp itself. However, any operating system which can utilize the BIOS emulation of Intel Macintosh can be made to work, including non-XP versions of Windows. The Ubuntu Linux distribution is particularly popular for this purpose because they provide an option to use proprietary device drivers along with open source drivers.
Vista problem with dual booting with XP
On a computer with both Windows Vista and either Windows XP or Windows Server 2003 installed, Windows XP or Windows Server 2003 deletes any existing System Restore points belonging to Windows Vista during boot.[1] Microsoft confirms this problem but maintains that it is a fundamental function of the way XP works and cannot be changed. According to Microsoft, the solution is to install Windows Vista on a separate partition invisible to XP.[2]
Windows and Linux
A popular multi-boot configuration is a mixed-OS system in which Linux is one of the secondary (or primary) installations. In terms of business strategy, Windows does not facilitate or support multi-boot systems, other than allowing for partition-specific installations, and no choice of boot loader is offered. However, most current Linux installers accommodate this problem, although some prior knowledge of partitions is desirable.
The basic concept involves partitioning a disk, to accommodate each planned installation, including separate partitions for data storage or backups. The partitions should be done with a Windows partitioning tool (diskpart, Disk Management), rather than a Linux tool (parted, QTparted), for the simple reason that Windows is more particular (i.e., "picky") about how the partition table is written and will occasionally complain or even show errors if it is installed to a Linux-created (or sometimes modified) partition table. Linux tools are powerful, (e.g., shrinking an NTFS drive) but Windows has particularities which must be considered. (See master boot record and extended boot record).
Windows should be installed to the first primary drive. Though Windows can be installed to another drive, certain particularities (drive letter assignments, expected system partition number) can make such installations problematic, while Linux installations on primary or logical drives have no such problems whatsoever.
The boot manager/loader should be installed by the Linux distribution. All Windows installations will be easily found by Linux, but Windows boot managers do not find Linux installations (nor does Windows deal natively with Linux file systems).
See also
- GNU GRUB
- Multiboot Specification
- NeoSmart Technologies' EasyBCD, a free program to configure Multi-booting on Windows
- XOSL, a free feature rich open source boot loader
- Chameleon (bootloader), an open source EFI bootloader for Mac OS X on x86 PCs
References
- ^ Al-Qudsi, Mahmoud (2007-12-16). "Vista Hide 'n Seek Beta". NeoSmart Technologies. Retrieved 2008-01-10.
- ^ "No restore points are available when you use Windows Vista or Windows Server 2008 in a dual-boot configuration together with an earlier Windows operating system". Microsoft Help and Support. Microsoft. 2008-01-31. Retrieved 2008-06-24.
External links
- Dual, Triple, Quad Boot a Macbook with Mac OS X, Ubuntu Linux, Windows XP, and Windows Vista
- The definitive dual-booting guide: Windows 7, Linux, Vista, XP: with screenshots.
- Installing Windows XP:Dual-Booting Versus Single Booting
- Instructions on how to make your Playstation 3 dual boot applicable
- Tutorial on multi-booting and solutions to issues that arise
- Information on Vista specific multi-booting issues