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WINDOWS OR LINUX By Greg Swain Dual Booting With Two Hard Drives Dual-boot set-up tutorials usually assume that you’re installing the two operating systems into separate partitions on the same hard disk drive (HDD). But what if you want to use two hard drives – one for each OS – and keep both bootloaders intact? D ESPITE USING WINDOWS in the work environment, I have also been a long-time user of Linux (Ubuntu) at home. Ubuntu is an easyto-use, stable operating system with a host of applications and is great for browsing the net (using Firefox) and for email and instant messaging. A big advantage of Linux is that it’s a very secure operating system. Certainly, you don’t have the worries about viruses and other internet nasties that you do with Windows. 14  Silicon Chip However, reality dictates that most people use Windows to run critical applications. This means that if you want to experiment with Ubuntu, a dual-boot system is the way to go. Taking it easy The most common path to a dualboot Windows/Linux system is to install Windows first and then install Linux onto a second partition on the same hard drive. If you do that, the Linux installer automatically recog- nise the presence of the Windows installation and includes it in the Linux bootloader (or at least, that’s what should happen). After that, you simply press the Esc key when prompted as the system starts up to bring up the boot menu. This allows you to select which operating system to boot. If you don’t do anything, the system automatically boots the default OS after a preset time. Similarly, if you install Windows on one hard drive and then subsequently siliconchip.com.au install Linux on a second hard drive, Linux should again detect the Windows installation and automatically set up with a dual-boot system. The only proviso here is that the Windows disk must remain as the primary drive (or have boot priority in the BIOS). Note that, in each case, the Windows bootloader is overwritten in the master boot record (MBR) by the Linux bootloader (known as “GRUB”) when you install Linux. This means that if you later reformat the Linux partition (or remove the Linux drive), then you will no longer be able to boot Windows unless you reinstate the Windows bootloader. Fig.1: the hard disk boot priority (ie, if your PC has two or more hard disk drives) is set up in the system BIOS. The system will boot from the first drive in the list, provided it has a valid operating system. Linux first? What if you install Linux first and then install Windows? Unfortunately, you don’t automatically get a dual-boot system, since the Windows installer will not recognise a Linux installation. Instead, it simply replaces the Linux bootloader in the MBR with its own and the system then only boots into Windows. The way around this is to reinstate GRUB as the system bootloader. Just how this is done is covered in some excellent guides on dual-boot systems published on the APC magazine website at http://apcmag.com/ howto_home.htm The APC guides cover all sorts of dual-boot scenarios involving Vista, XP and Linux – eg, Vista and Linux, XP and Linux, and Vista and XP. It doesn’t matter which system you install first; the APC guides have it covered. We don’t intend to repeat what’s in those guides here. Instead, we will concentrate on one dual-boot scenario that’s not in the APC guides and that’s where Windows and Ubuntu Linux have been independently installed on separate hard disk drives (ie, with only one disk drive connected during each install). Why separate HDDs? There are several reasons why you might want to keep the two operating systems on separate disk drives. First, while a single-disk dual-boot Windows-Linux system works perfectly well, what if you want to later completely blow the Linux installation (including the GRUB bootloader) away? As stated above, the answer is to reinstall the Windows bootloader in the siliconchip.com.au MBR and while it’s a straightforward procedure, you still have to do it (and risk something going wrong). There’s also a risk that you might foul up an existing Windows installation if you do the wrong thing when installing Linux. And that can be easy to do when it comes to altering partition sizes and formatting partitions for the Linux installation (even with two disk drives), particularly if you’re inexperienced. By far the safest route to a dual-boot system is to install each operating system onto its own hard disk drive, with only one disk connected during each install. That way, you can not possibly foul up an existing install­ ation on the other (disconnected) drive when installing the second OS. It also means that the bootloader for each operating system is kept intact on its own drive. The basic scenario OK, so here’s the basic scenario. First, you’ve installed Windows Vista (or Windows XP) on one hard drive and got it all working correctly. You’ve then disconnected that drive from your computer, plugged in a second hard drive and installed Ubuntu. Finally, having done all that, the first drive has then been reconnected. The result is a machine with two hard disk drives, one with Windows installed and the other running Ubuntu. Of course, it won’t be a dual-boot arrangement but you can choose which OS you want to boot simply by changing the hard disk boot priority order in the system BIOS – see Fig.1. If you give the Windows disk priority, the system will boot into Windows. If you move the Linux disk to the head of the queue, the system will boot into Linux. As indicated previously, the beauty of this scheme is that the bootloader of each operating system is left intact. That means that you can remove either disk and the operating system on the remaining disk will boot normally. It’s also a very safe set-up that’s easy to convert to dual-boot. Dual booting Unless you rarely use one OS, having to get into the system BIOS to change the disk boot priority is not the way to go. Instead, it’s better to convert the system to dual-boot, so that you can choose which OS you want from a boot menu. That’s done by modifying the bootloader on one disk and giving that disk boot priority. In other words, you can Changing Disk Drive Boot Priority If your PC is less than about five years old, you can change the hard disk boot order in the system BIOS (see Fig.1). This should cater for both SATA and IDE drives (or a mixture of both) – it’s just a matter of moving the desired boot drive to the head of the queue. On older systems with IDE-only drives, it might not be possible to do this in the BIOS. Instead, you will have to change the boot priority using one of two methods: (1) plugging one drive into the primary IDE port and the other into the secondary port; or (2) where both drives are on the same IDE cable, by changing the master/slave jumpers on the drives (the master drive boots first). January 2009  15 either modify the Windows bootloader and give the Windows disk boot priority in the system BIOS, or you can modify the Linux bootloader and give the Linux disk boot priority. We’ll look at both methods here but first, be sure to back up any critical data that you might have on the two disks. Both dual-boot methods are quite simple to implement but backing up is always a worthwhile precaution, as accidents can occur (you could drop a disk, for example). Using the Linux bootloader Fig.2: setting the timeout value and commenting out the “hiddenmenu” line in GRUB’s menu.lst file. Fig.3: placing the Windows boot entries just above the “### BEGIN AUTOMAGIC KERNELS LIST” entry in GRUB’s menu.lst file makes Windows the default. If you want Ubuntu to be the default, insert the Windows entries after the “### END DEBIAN AUTOMAGIC KERNELS LIST” line. The easiest method is to modify the Linux bootloader (known as “GRUB”) and this will work equally well for a Vista-Linux system or an XP-Linux system. All you have to do is edit the /boot/grub/menu.lst text file which GRUB uses to store the boot options. Here’s the step-by-step procedure: STEP 1: go into the system BIOS and give boot priority to the Ubuntu hard disk (see Fig.1). STEP 2: boot into Ubuntu and make a backup copy of the GRUB boot menu. Do this by copying the file /boot/grub/ menu.lst to an external flash drive (or to some other location). STEP 3: enter sudo gedit /boot/grub/ menu.lst in a terminal window and type in the root password at the prompt. This will open the menu.lst text file in the gedit text editor. STEP 4: scroll down the file and change the timeout line to a suitable value (see Fig.2). This value sets the boot menu display time (in seconds) during startup. A value of 5 to 7 should be ideal (the default is 3). STEP 5: comment out the hiddenmenu line by inserting a “#” character at the start of the line (see Fig.2). This ensures that the boot menu is shown at system start-up. STEP 6: scroll down and locate the line “### BEGIN AUTOMAGIC KERNELS LIST”. If you want Windows to be the default, then insert the following entries into menu.lst above this line, as shown in Fig.3: title rootnoverify makeactive map map chainloader Fig.4: this is the resulting GRUB boot menu that appears at system start-up. 16  Silicon Chip    Microsoft Windows Vista (hd1,0) (hd0) (hd1) (hd1) (hd0) +1 This adds Windows Vista to the GRUB bootloader. Alternatively, if you want Ubuntu siliconchip.com.au to be the default OS, then scroll down further and locate the “### END DEBIAN AUTOMAGIC KERNELS LIST” entry in menu.lst. Insert the Windows Vista boot entries after this line (ie, the first entry is the default operating system. If you have XP instead of Vista installed, simply change the title line to “Microsoft Windows XP”. Note that you should keep the Windows boot entries out of the area between the begin and end AUTOMAGIC KERNELS LIST lines. If you don’t do this, the Windows boot entries will be overwritten during the update-grub process each time the kernel is updated. Keeping the Windows boot entries outside this area ensures that they remain static and won’t be lost during kernel updates (not that it’s really any great hardship to re-enter the necessary lines). STEP 7: save the menu.lst file, exit Linux and reboot the machine. That’s it – you now have a fully-functioning dual-boot system. Each time the machine starts, the GRUB boot menu will appear and you will be able to choose between Windows and Ubuntu – see Fig.4. Fig.5: managing the Vista bootloader is easy with EasyBCD. Here’s how to install NeoGrub, to dual-boot Linux. Breaking up is easy to do Divorcing the two systems couldn’t be easier. As indicated previously, the bootloader on each disk is left intact, so if you remove one disk, the system will still boot into the OS on the remaining disk. Of course, if you remove the Windows disk, the Windows entry will still appear on the GRUB boot menu when you boot Linux. That can be fixed by simply deleting the Windows boot entries from the menu.lst file. Note also that if you change the disk boot priority in the BIOS and subsequently make the Windows disk number one, then the system will always boot into Windows. It will be as though the Linux disk doesn’t exist. This means that you must assign boot priority to the Linux disk in the system BIOS if you want GRUB to bring up the dual-boot menu at system start-up. Using the Windows Vista bootloader If you’re happy with the GRUB bootloader (and why not?), then you don’t have to go any further. However, if you have Vista and Linux set-ups and want to dual-boot using the Windows bootloader, then that’s also easy to do. Adding the Linux boot entries to the Vista bootloader is best done using a program called EasyBCD from NeoSmart Technologies. This freeware program has an easy-to-use graphical interface that makes tweaking the Vista bootloader a breeze. Note: EasyBCD is for use with Windows Vista only – it can not be used with Windows XP. OK, let’s go through the procedure step-by step: STEP 1: give the Ubuntu disk boot priority in the BIOS, then boot Ubuntu. STEP 2: enter sudo gedit /boot/grub/menu.lst in a terminal window and type in the root password when prompted. This will open the menu.lst text file. STEP 3: scroll down to the end of the file and locate the Linux boot entries between “## ## End Default Options ##” and “### END DEBIAN AUTOMAGIC KERNELS LIST”. Copy these entries, paste them into a new text file and save the file to an external USB drive (eg, a flash drive). STEP 4: exit Ubuntu, then modify the BIOS to give the Vista disk boot priority and start Windows. siliconchip.com.au Fig.6: clicking “Install NeoGrub” (Fig.5) adds the NeoGrub Bootloader under the existing Windows Vista entry. Fig.7: you can also change various settings in EasyBCD includ­ing the default OS and the menu timeout (seconds). January 2009  17 Fig.8: the Ubuntu boot entries in /boot/grub/menu.lst (on the Linux disk) are copied and pasted into the NeoGrub configuration file at C:\NST\menu.lst on the Windows disk. This enables the Vista bootloader to dual-boot Vista and Linux. Don’t forget to change all (hd0,0) entries to (hd1,0). Fig.9: once it’s all working, the Vista bootloader displays the Vista and NeoGrub boot options in the menu at system start-up. STEP 5: download and install EasyBCD. You can grab it here: http:// neosmart.net/dl.php?id=1 STEP 6: launch the application and click on the Add/Remove Entries button to bring up the dialog shown in Fig.5. STEP 7: click on the NeoGrub tab, then click the Install NeoGrub button. The “NeoGrub Bootloader” entry will be added beneath the existing “Microsoft Windows Vista” entry (Fig.6). STEP 8: click Configure. This creates the NeoGrub menu.lst file in the C:\NST folder. This file is analogous to the menu.lst file in Ubuntu, except that it’s initially almost empty. STEP 9: open C:\NST\menu.lst in Notepad and paste in the Linux boot entries that you previously saved on your USB drive. STEP 10: change all (hd0,0) entries in the menu/lst file to (hd1,0) – see Fig.8. This is necessary since Ubuntu in now on hard disk 1, partition 0 (as opposed to hard disk 0, partition 0 when the Linux drive has boot priority). STEP 11: save the C:\NST\menu. lst file, exit Notepad and reboot the computer. You now have a working dual-boot system using the Vista bootloader. When the machine restarts, it will display a boot menu with two options (see Fig.9): (1) Microsoft Windows Vista; and (2) NeoGrub Bootloader. Selecting the latter will bring up the Linux boot options shown in Fig.10. Kernel updates One drawback of using the Vista bootloader is that the C:\NST\menu. lst file will not be automatically updated if you update the Linux kernel. This means that if you do update the kernel, then you will have to copy the updated boot entries from /boot/ grub/menu.lst (on the Linux drive) to the C:\NST\menu.lst file on the Windows drive. Don’t forget to change the (hd0,0) entries to (hd1,0) each time you do this. GRUB is more convenient Fig.10: selecting the NeoGrub Bootloader option from the menu brings up the Linux boot options. If no further action is taken, the default will load at the end of the timeout period set in C:\NST\menu.lst. 18  Silicon Chip Using the GRUB bootloader is slightly more convenient if only because you don’t have to edit C:\NST\ menu.lst every time you do a kernel update. The GRUB bootloader is also slightly easier to set up but in the end, SC the choice is yours. siliconchip.com.au