Re: Windows multiboot (aaargh!)

[Carel Fellinger <carel.fellinger@chello.nl>]

On Thu, Sep 11, 2003 at 12:07:08AM +1200, cr wrote:
> This may seem an odd place to ask this, but I'll bet some of the folks on 
> this list know more about the technicalities of booting Windoze than Windoze 
> users do   ;)

I know next to nothing about Windows and prefer to keep it like that:),
but as I've kids that, like kids like, like to play games, I've been
forced to atleast find out how play this trick.  (example at the end)

>From experience, Win95/98 needs to be on the first drive, needs to be
in a bootable primary partition which needs to be the only/first primary
partition.

Don't despair, GRUB is perfectly capable of _hiding_ specific partitions
in the bootprocess, and many(?) BIOSses allow to swap the order of drives.

So create on the disk of choice enough primary partitons, use GRUBS to
hide all but one, swap the BIOS drive order such that the drive of
choice seems to be the first one, and all is swell.

Well it should be, but experience has learned me otherwise:(
The biggest problem being ghost/phantom drives appearing under windows.

I used to think it was related to windows weared way of determining to
use or not to use lineair addressing mode on large drives, and hence
its inability to obey the partitioning scheme used.  So I was very
carefull to partition disks in such a way that the 1024 cylinder (this
being one of the clues windows uses) felt on a partition boundary.

But nowadays I think that what's really needed is to take care that all
windows partitions have there first sector(s?) cleaned prior to letting
windows format those, as it seems that windows prefers the partitioning
information it finds in that(those) first sector(s) to the real partition
table, and what is worst, there is a bootstrap problem as windows format
prog assumes that info is valid and hence will use it unless it's cleared.


As far as I know the 1024 cylinder thing is still very much relevant
to Win95 as wel as chosing the right partition type, so probably the
safest is to partition carefully.  And be warned, I've lost linux
partitions (on my fathers machine thanks to my sister) using windows
tools to repartition, reformat and reinstall windows:(  --this was
prior to me being very carefull to wipe the first sector, so maybe it
works better now.  Anyway, i've always used linux tools to do the
partitioning, the only way for me to be able to _predict_ the end
result--


...
> I'd like to be able to boot into DOS, Win95 and Win98.
...
> I'm just wondering how practical that is.    Can W95 and W98 coexist on the 
> same disk in diferent partitions and still both be bootable?    If not, any 

Yes, that's what I've been doing for years.  Though the safest thing
would be to have seperate disks for each windows install and use the
BIOS capability to swap drives, you could do like I do (and pray:).


My disks lookes like:

    # two bootable windows partitions on hda
    # one bootable windows partition on hdb


My /boot/grub/menu.lst lookes like:

    title   Windows from second disc
    map (hd0) (hd1)
    map (hd1) (hd0)
    root    (hd1,0)
    makeactive
    chainloader +1
    
    
    title   Win95 from first disc second partition
    hide    (hd0,0)
    unhide  (hd0,1)
    root    (hd0,1)
    makeactive
    chainloader +1
    
    
    title   Win98 from first disc first partition
    unhide  (hd0,0)
    hide    (hd0,1)
    root    (hd0,0)
    makeactive
    chainloader +1
    
    

-- 
groetjes, carel