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93 lines
4.7 KiB
Plaintext
93 lines
4.7 KiB
Plaintext
Boot Manager Selection:
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-----------------------
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If you wish to switch between multiple operating systems on your
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machine, or if you are trying to install FreeBSD on a drive other than
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your 1st drive, then you must install a boot manager. In the case
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where you wish to boot off an alternate drive, it should also be noted
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that you still need to install a boot manager on the FIRST drive!
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Even if you do not intend to create a FreeBSD partition on that drive
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(e.g. it's being wholly used by something else), the boot manager
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still needs to reside on the first disk in order to function as a
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"redirector" for the boot process.
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To do this, simply select your 1st drive in the drive selection menu
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and when the partition editor comes up, don't make any changes - just
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(Q)uit. At the boot manager menu which follows, select the first
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option (install a boot manager) and then proceed to setup the other
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drive(s) for FreeBSD as normal.
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It should also be noted that "operating systems" such as Windows 95
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will completely overwrite your boot manager without so much as a
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polite "may I please destroy your boot manager?" prompt if you make
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the mistake of installing them second. If this happens to you after
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FreeBSD is already installed, all is not lost! Simply revisit your
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FreeBSD distribution directory and look for a tools/ subdirectory, in
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which you'll find "bootinst.exe" and "boot.bin". To reinstall, simply
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say "bootinst boot.bin" while in the tools/ subdirectory.
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If you see the boot manager displaying ``F?'' when you try to come up
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for the first time and it refuses to change, no matter how often you
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whap on the function key assigned to FreeBSD, then you have a geometry
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mismatch problem and you should read the next section for important
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information on how to prevent that exact problem from happening!
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Geometry Translation / Sharing the disk(s) with another OS:
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----------------------------------------------------------
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If you are going to actually install some portion of FreeBSD on a
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drive then PLEASE BE VERY CERTAIN that the Geometry reported in the
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Partition Editor is the correct one for your drive and controller
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combination!
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IDE drives often have a certain geometry set during the PC BIOS setup,
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or (in the case of larger IDE drives) have their geometry "translated"
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by either the IDE controller or a special boot-sector translation
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utility such as that by OnTrack Systems. In these cases, knowing the
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correct geometry gets even more complicated as it's not something you
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can easily tell by looking at the drive or the PC BIOS setup. The
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best way of verifying that your geometry is being correctly calculated
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in such situations is to boot DOS (from the hard disk, not a floppy!)
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and run the ``pfdisk'' utility provided in the tools/ subdirectory of
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the FreeBSD CDROM or FTP site. It will report the geometry that DOS
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sees, which is generally the correct one.
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If you have no DOS partition sharing the disk at all, then you may
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find that you have better luck with Geometry detection if you create a
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very small DOS partition first, before installing FreeBSD. Once
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FreeBSD is installed you can always delete it again if you need the
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space.
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It's actually not a bad idea (believe it or not) to have a small
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bootable DOS partition on your FreeBSD machine anyway: Should the
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machine become unstable or exhibit strange behavior at some point in
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the future (which is not uncommon behavior for PC hardware!) you can
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then at least use DOS for installing and running one of the
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commercially available system diagnostic utilities.
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IMPORTANT NOTE:
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Any root partition you try to boot from must also reside below the
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1024th cylinder. If you're using a translated geometry then this is
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probably not a problem, but if you are using a native disk geometry
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which exceeds 1024 cylinders then you could have a failure to boot if
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you end up installing a root partition (or even just the kernel file
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in a root partition) out past cylinder 1024. If you are trying to
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share your first disk with FreeBSD and another OS which was installed
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previously, you are particularly susceptible to this problem and should
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check your disk addresses very carefully.
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If you find that you have insufficient space below cylinder 1024 to
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make a root partition for FreeBSD (and again, this ONLY applies to the
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root partition - once FreeBSD's kernel is loaded, it doesn't care
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about the geometry issues) then you will probably need to install on a
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completely different disk (see the boot manager section above) or
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resize your existing partitions so that both operating systems can
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have boot partitions below cylinder 1024.
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You may blame IBM for the limitations of a 10 bit cylinder address.
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"No one will have a disk with more than 1024 cylinders." I'm sure
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someone said.
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