"A Duel" boot

[gugin]

Does anyone know how to dual boot 10.6 and Windows 7 so they dont have a duel?

 

I have 10.6 working. My partition scheme is as follows:

 

/dev/disk0

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *320.1 GB disk0

1: EFI 209.7 MB disk0s1

2: Apple_HFS Snow Leopard 160.0 GB disk0s2

 

I would like to have windows 7 64-bit too. As you can see 10.6 64-bit is on the first partition and the rest is unformatted. So, I think I did it in reverse according to the guides I've read on here. So, is there a good way to do it without killing a poor defenseless snow leopard? The other day I had windows 7 64bit installed and when I configured my bios to install snow leopard my computer wouldn't boot at all. It just hung after it posted.

[srs5694]

The simplest and safest method is to buy a second hard disk and install Windows there. That way you don't need to mess with repartitioning or implementing weird partitioning schemes like hybrid MBRs, and you can physically disconnect one disk when you want to do something risky (like install Windows).

 

Failing that, I'd say to do the following (this is a rough guide; use any of the bazillion more specific guides to fill in the gaps):

 

1. Shrink your existing OS X partition. Disk Utility can do this, although you might need to boot the install disc to do it (I'm not sure if it'll work on a mounted disk).
   
2. Create a partition just after the OS X partition for shared data, if desired. Either format it for FAT or don't format it at all just yet. If you have problems doing this with Disk Utility, you can use GPT fdisk (described shortly) to do the job. If you use GPT fdisk, be sure to include 128MB of blank space after the OS X partition. (You can specify the starting sector as "+128M" to do this.)
   
3. Create a partition just after the shared-data partition, at the very end of the disk, for Windows. Either format it for FAT or don't format it at all just yet. Note that putting Windows last on the disk is best, IMNSHO, for hybrid configurations, since that enables the protective MBR's EFI GPT partition to do what it's supposed to do: Keep GPT-unaware utilities from messing with the disk.
   
4. Use my GPT fdisk program to create a new hybrid MBR. (See the hybrid MBR page of its documentation for detailed instructions.) Include the shared-data and Windows partitions in the hybrid MBR. If you formatted them for FAT, give them MBR type codes of 0x0c; if you left them unformatted, give them type codes of 0x07.
   
5. Make backups of your GPT partitions and of the MBR data. GPT fdisk includes a backup function ('b' on the main menu). To back up the MBR, use dd: "dd if=/dev/disk0 of=backup.mbr bs=512 count=1"). Put both backups on a readily-accessible removable medium, such as a USB flash drive. In an emergency, you might need to restore one or both from a Linux emergency disk such as System Rescue CD.
   
6. Reboot into the Windows installer.
   
7. Install Windows normally. You'll have to format the installation partition. (The installer may do this automatically; I don't recall.) In a worst-case scenario, if the installer doesn't like the target disk, you might need to boot a Linux emergency system and use the mkfs.ntfs command to format the target partition as NTFS, and use Linux fdisk to change its MBR type code to 0x07. You should then be able to reboot the installer and install.
   
8. At this point the system will only boot Windows. You can restore OS X to bootability several ways, such as booting the OS X install disc and using it to re-install your boot loader or using a Linux emergency disk and copying back the MBR backup you made earlier. (The command will be "dd if=backup.mbr of=/dev/sda" or something similar, depending on the filenames for the backup and the device file.) If you use the Linux method, you may need to use its fdisk to change the partition type code(s) of the Windows partitions to 0x07.
   

[gugin]

The simplest and safest method is to buy a second hard disk and install Windows there. That way you don't need to mess with repartitioning or implementing weird partitioning schemes like hybrid MBRs, and you can physically disconnect one disk when you want to do something risky (like install Windows).

 

Failing that, I'd say to do the following (this is a rough guide; use any of the bazillion more specific guides to fill in the gaps):

 

1. Shrink your existing OS X partition. Disk Utility can do this, although you might need to boot the install disc to do it (I'm not sure if it'll work on a mounted disk).
   
2. Create a partition just after the OS X partition for shared data, if desired. Either format it for FAT or don't format it at all just yet. If you have problems doing this with Disk Utility, you can use GPT fdisk (described shortly) to do the job. If you use GPT fdisk, be sure to include 128MB of blank space after the OS X partition. (You can specify the starting sector as "+128M" to do this.)
   
3. Create a partition just after the shared-data partition, at the very end of the disk, for Windows. Either format it for FAT or don't format it at all just yet. Note that putting Windows last on the disk is best, IMNSHO, for hybrid configurations, since that enables the protective MBR's EFI GPT partition to do what it's supposed to do: Keep GPT-unaware utilities from messing with the disk.
   
4. Use my GPT fdisk program to create a new hybrid MBR. (See the hybrid MBR page of its documentation for detailed instructions.) Include the shared-data and Windows partitions in the hybrid MBR. If you formatted them for FAT, give them MBR type codes of 0x0c; if you left them unformatted, give them type codes of 0x07.
   
5. Make backups of your GPT partitions and of the MBR data. GPT fdisk includes a backup function ('b' on the main menu). To back up the MBR, use dd: "dd if=/dev/disk0 of=backup.mbr bs=512 count=1"). Put both backups on a readily-accessible removable medium, such as a USB flash drive. In an emergency, you might need to restore one or both from a Linux emergency disk such as System Rescue CD.
   
6. Reboot into the Windows installer.
   
7. Install Windows normally. You'll have to format the installation partition. (The installer may do this automatically; I don't recall.) In a worst-case scenario, if the installer doesn't like the target disk, you might need to boot a Linux emergency system and use the mkfs.ntfs command to format the target partition as NTFS, and use Linux fdisk to change its MBR type code to 0x07. You should then be able to reboot the installer and install.
   
8. At this point the system will only boot Windows. You can restore OS X to bootability several ways, such as booting the OS X install disc and using it to re-install your boot loader or using a Linux emergency disk and copying back the MBR backup you made earlier. (The command will be "dd if=backup.mbr of=/dev/sda" or something similar, depending on the filenames for the backup and the device file.) If you use the Linux method, you may need to use its fdisk to change the partition type code(s) of the Windows partitions to 0x07.
   

 

 

wow A lot of good info. Thanks.