Dual-boot WinXP: FreeBSD slice within 8GB? Space for EasyBoot?

Maude User maudeuser at yahoo.com
Mon Mar 28 13:40:08 PST 2005


Hello -
 
I'm going to install FreeBSD to make a dual-boot laptop (keeping WinXP-Pro). It has 60GB on a single hard drive, currently one big NTFS "partition" (C:) - which I will shrink down to about 16GB with PartitionMagic, leaving a new generic FAT or FAT32 slice which FreeBSD will overwrite. 
 
I have 2 questions:
 
(1) Does the FreeBSD slice have to start before 8GB to be bootable?
 
(2) Is there free space before the WinXP slice already for EasyBoot?
 
Thanks.
 
- Stefan
 
 
 
Further details below:
 
(1) Does the FreeBSD slice have to start before 8GB to be bootable?
===================================================================
This is a new machine, so I assume I have BIOS LBA, which got rid of the dreaded "1024 cylinder limit". But the link below (very optimistic, but talking about hard drive with only 1.6GB, way less than 8GB) implies that even with BIOS LBA, my FreeBSD slice still needs to start before 8GB:
 
http://geodsoft.com/howto/dualboot/"With BIOS LBA, the hard disk size limitation is virtually removed (well, pushed up to 8 Gigabytes anyway). If you have an LBA BIOS, you can put FreeBSD or any OS anywhere you want and not hit the 1024 cylinder limit."
 
I know people say that FreeBSD can boot from "anywhere" - but even if its slice starts way out around 20GB??
 
 
(2) Is there free space before the WinXP slice already for EasyBoot?
====================================================================

 
http://www.freebsd.org/doc/en_US.ISO8859-1/articles/multi-os/x191.html
"Some operating systems (FreeBSD included) let you start their partitions right after the Master Boot Sector at Cylinder 0, Head 0, Sector 2 if you want. ... Then when you go to install your boot manager, if it is one that occupies a few extra sectors after the MBR, it will overwrite the front of the first partition's data. In the case of FreeBSD, this overwrites the disk label, and renders your FreeBSD partition unbootable.
The easy way to avoid this problem (and leave yourself the flexibility to try different boot managers later) is just to always leave the first full track on your disk unallocated when you partition your disk. That is, leave the space from Cylinder 0, Head 0, Sector 2 through Cylinder 0, Head 0, Sector 63 unallocated, and start your first partition at Cylinder 0, Head 1, Sector 1. For what it is worth, when you create a DOS partition at the front of your disk, DOS leaves this space open by default (this is why some boot managers assume it is free). So creating a DOS partition up at the front of your disk avoids this problem altogether. I like to do this myself, creating 1 Meg DOS partition up front, because it also avoids my primary DOS drive letters shifting later when I repartition."

As my laptop already has a DOS (WinXP-NTFS) slice at the beginning of the hard drive, can I just shrink this slice down to about 20GB, install FreeBSD on the slice after that, install EasyBoot, and assume that EasyBoot will be tucked into that sliver of free space before Cylinder 0, Head 1, Sector 1?

Thanks,
Stefan
 
 


		
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