Post by A.D. FundumWhat's required to have both Windows 7 and eCS 1.2 working with the
OS/2 bootmanager?
The partition records of Windows 7 cannot be read by eCS 1.2
and the eCS bootmanager cannot boot a system which uses 2 partitions
at boottime -- as Windows 7 prefers to do.
Here is my recipe, to boot Windows 7, OS/2 and Debian Linux, using
http://www.dfsee.com/dfsee/
I had installed OS/2, partitioned the hard disk with the Logical Volume
Manager and DFsee such that the first primary partition starts at
CHS = 0-32-33, because earlier attempts had shown that Windows 7
chooses this offset and repartitions it if the primary partition starts
earlier.
It is advisable to use a second primary partition for an additional
operating system and the third for the IBM bootmanager. The additional
partitions are logical partitions in an extended partition, which by
construction is then the fourth primary partition. This prevents
Windows from creating an additional primary partition for its system
files, because a disk can have 4 primary partitions at most.
(If one hasnt used up enough partitions, then Windows 7 creates two
partitions partitions without asking, one partition of about 100 MB for
system files:) A second primary partition for Windows 7 prevent s
it to boot with the IBM bootmanager, as during boot the bootmanger
hides all but the chosen partition. This I learned from Jan van Wijk,
the author of DFSee.
Next I created a bootable USB-stick with DFsee and FreeDos
to have access to the partition tables no matter which operation
system is installed and operative at the harddisk.
With DFsee I made a backup of the partition tables created under OS/2.
Then I installed Debian Linux (squeeze) and forced its bootmanger grub2
not only to install itself in the masterboot record (which one cannot
prevent during installation) but also in the bootrecord of its own
partition (sda6)
update-grub
grub-install /dev/sda6 --force (replace sda6 as appropriate)
Then I restored with DFsee the OS/2 partition tables with exception of
the partition boot records. This enabled dual boot of OS/2 or Debian
Linux with the IBM bootmanager who hands over to grub2.
It is not sufficient, to restore the first block (512 Byte)
of the masterboot record, as widespread recipes suggest. Grub2 changes
also the extended boot record and makes it unreadable for OS/2 LVM.
I used Linux to format partition 1 (sda1) with NTFS
mkfs.ntfs /dev/sda1
and included the Windows partition in the IBM bootmanger menu.
The Windows 7 installation accepted the partition 1 for installation
without any change and even proceeded without formatting it anew. It did
not create an additional partition (which it had done previously when
another primary partition was possible, because at that time I had used
only three.)
Of course, Windows changed the partition tables such that the IBM
bootmanager did no longer take over at boot time.
But with the bootable USB-stick and and DFsee one can repair this. It
is not sufficient to set the startable flag with e.g. Knoppix to the
Bootmanager partition. The bootmanger does not start with the
bootrecord written by Windows.
Also one cannot just restore the OS/2 partition boot records, as then
Windows complains at bootup about a device which it cannot find, asks
to be repaired and after some minutes reports that the attempt to
repair failed.
To repair the boot record one has to execute in the DFsee menu
FDISK, OS/2 LVM and Bootmanger, BMGR W2K CHS and I13X fix
and
FDISK, Part-table cleanup repair, Cleanup partition table
and reboot via
File, Boot using IBM bootmanger, Windows
Of course, one has to remove the USB-stick before reboot.
Windows started with no trace of the bootmanger, but on the next
reboot the IBM bootmanger took over and allows now to boot
Windows 7 or OS/2 or Debian Linux.
Under Linux
update-grub
will find Windows 7 and enable to chainboot Windows if one boots
Linux with the IBM bootmanger. But if Windows 7 is installed in only
one partition this chainboot is not required.
Finally I made a backup of the partition tables of the working triple
boot installation.
--
Superstition brings bad luck.
www.itp.uni-hannover.de/~dragon