# Install FreeBSD with other OS on the same disk



## ufbsd (Nov 10, 2012)

Hello.

I have already installed Linux and Windows. In MBR is a Windows Boot Loader. I want to install FreeBSD now. I have 2 free partitions on the MBR disk: one primary and one extended for swap. I don't want to erase MBR, I want to install FreeBSD boot loader into this free primary partiton and then I will make it active and I hope run FreeBSD. I have read installation instructions but i didn't understand exactly. There are 3 boot loaders: boot0,boot1,boot2. Seems to be boot0 is the MBR code and 446 bytes length, boot1 is 512 bytes length. What is the difference between them?

My main Questions:
1) I don't want to replace my current MBR code. Is it possible to install boot1 and boot2 to the same primary partition? And so what partitions I must to choose during installation for FreeBSD? Is it enough to choose only freebsd-ufs an freebsd-swap for root and swap without freebsd-boot?

2) I also want to start FreeBSD from GRUB boot menu(GRUB is installed into another primary partition). What exactly I must to write to the GRUB menu to start FreeBSD after installation?


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## jb_fvwm2 (Nov 10, 2012)

I've dual booted windows-98 with both BootIt and gag... However since that time the installers have changed, the GEOM class drivers have changed, mbr > gtp; etc etc.  So all I can suggest is search the forum for posts containing grub(2)... and be sure to have backups (Also search the forum for posts where a dual-boot : "now windows can't boot" etc...) for the recovery procedure(s).


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## wblock@ (Nov 10, 2012)

MBR doesn't need or use a freebsd-boot partition.  But you are wasting a whole primary partition on grub?  EasyBCD works fine, and doesn't need another partition.

boot0 is the FreeBSD multi-boot loader.  It is only code that goes in the MBR, less than 512 bytes.  The non-multi-boot version is mbr.

I don't know if there is a way to get bsdinstall(8) to install for multi-boot.  Likely it just always installs the plain MBR.

Two pieces of advice:
1. Back up that whole disk first.  All of it, the boot blocks and every partition, contorted multi-boot stuff included.
2. Skip this multi-boot stuff and install VMs.  They are safer, easier, and more versatile.


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## mike4 (Nov 11, 2012)

Not sure but I think grub detects also FreeBSD as it also does OSX etc.
And no special partition is needed. Simply install Ubunutu or if already installed do something alike:
sudo update-grub
I boot with Grub osx86, win8 and 2 Ubuntu. I'll add FreeBSD 9.1 when it's final.


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## hostinfo (Nov 12, 2012)

Make new partition from some bootable disks, like hirens boot disk, it will help to make exactly partition on previous disks.


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