Question for ***LINUX***** gurus.

[bvar22]

What is the Linux utility that would correspond to the DOS FDISK ?


I am installing Mandrake 10.0 on a Multiple Primary Partition box (multi OS), and I need to be able to select which Primary Partition to Set "Active" for the next boot.
How can I do this from inside Mandrake?

Thanks.

[bemildred]

1. Have you tried: "man fdisk"?

One usually tries to arrange to select which OS to boot
at boot time, and the little bit of code that does this is
called a "boot manager" and lives in boot sector zero.

This is what "man fdisk" says on FreeBSD:

NAME
fdisk - PC slice table maintenance program

SYNOPSIS
fdisk <-BIaistu> <-b bootcode> <-1234>
fdisk -f configfile <-itv>

PROLOGUE
In order for the BIOS to boot the kernel, certain conventions must be
adhered to. Sector 0 of the disk must contain boot code, a slice table,
and a magic number. BIOS slices can be used to break the disk up into
several pieces. The BIOS brings in sector 0 and verifies the magic num-
ber. The sector 0 boot code then searches the slice table to determine
which slice is marked active. This boot code then brings in the boot-
strap from the active slice and, if marked bootable, runs it. Under DOS,
you can have one or more slices with one active. The DOS fdisk program
can be used to divide space on the disk into slices and set one active.

etc.

[bvar22]

2. I haven't tried yet.

I'm experimenting with a Multiple OS scheme that doesn't use a Boot Manager.
Instead of a Boot Manager, I'm using different primary partitions to house the different Operating Systems. Only the "Active Primary Partition" is visible to the Operating System in use. The other Primary Partitions are hidden. Files on the Logical Drives are visible from each OS, and the Drive Letters are consistent.

Some of the advantages are:

NO Boot Manager

No Installation Hassels, install in any order.

Each Operating System is Pristine and installed directly into its own partition.


This is achived by using a small utility that comes with Partition Magic 8.0, called PQBoot. You simply run PQBoot before shutdown, select the desired partition to make ACTIVE, and reboot.

I experimentally installed XP, Me, and Win98 on the same drive. It works beautifully.

I was hoping to use this scheme to install Mandrake, but I need a way of booting back to XP (PQBoot not available ? for Linux).

I tried booting from a floppy and using FDISK, but that didn't work (so far). FDISK let me change the ACTIVEPrimary Partition, but I was unable to change the drive status from hidden(which PQBoot was doing automatically).

I can run Partition Magic from a floppy and effect these changes, but that is way too much hassel. I would love a utility in Mandrake that would allow me to change the active partition AND allow me to designate hidden or unhidden.

The only drawback to this scheme is that you have to decide which system you want to boot to next BEFORE you shut down.



Hope I explained clearly.

BTW: Partition Magic 8.0 has TERRIBLE problems in XP.

[bemildred]

3. "Hidden" and "Unhidden" are not Linux concepts, AFAIK.

One simply fails to mount filesystems one does not want to look at.
Access rights are handled in a completely different way from Windoze
OSes.

Hence, I think you are out of luck with finding a PQboot replacement.
Fdisk will handle the "set active partition part", and read and write
BIOS partition tables, and so on, just like the DOS version.

I can't say I see why you think not having a boot manager is a good
thing, unless you mean something different than I do by the term.

[bvar22]

4. A Boot Manager is just something I would...

...like to avoid if possible. One more layer of hassel if you like to play with the nuts and bolts.

I used to play with NT, Win311, and Warp (remember that?). I used a Boot Manager (System Commander) to jump between systems. Every time I wiped out or replaced an OS, I had to either update or work through the Boot Manager or bad things would happen. The Boot Manager also put extra files in in root directories of the OSes.

There are several options I'm still considering. (GDISK, PQBOOT for Linux)

Thanks for your input, bemildred. I've watched the advice you have given to others in this forum and I trust your judgement and knowlege.

I will inevitably end up the Linux dual boot the wise are counseling, but I'm having too much fun playing with this scheme to quit now.

I'm curious now if Mandrake will see my hidden partitions.
I have everything backed up and plenty of time (CSPAN on the TV, and AAR on the radio). If I trash the whole box, I'll log on to DU with my notebook.

Thanks for your help.

BTW: I have experience in PCs, but am a Linux novice.
I ran KNOPPIX from CD earlier today and loved it. My system was very agreeable with KNOPPIX...everything worked.
Would you recommend Mandrake for me, or is another version preferable?
I already have the disks for Mandrake 10.

Thanks again.

[bemildred]

5. I see I was correct.

(That we do not mean the same thing by "boot manager".)

My boot manager works like this:

1.) Boot PC, BIOS screen passes by ...
2.) Bios then runs disk master boot record (MBR), which displays
something like this:

System to boot (Default F1):
F1: DOS
F2: BSD
(up to four physical partitions)

And then boots the one I select. Hence I can switch back & forth as
needed by rebooting. I have done up to four (BSD, Linux, DOS, Win98),
but the M$ OSes can see each others drives. There is nothing put in
any directories, nothing besides what goes in the drive MBR.

---

Linux, IIRC, allows you to use a floppy to select an OS to boot.

I use the FreeBSD BOOTANY boot manager, it's one reason I use
FreeBSD, I set up the disk in FreeBSD and install it, then install
other OSes, then go back and reinstall the BOOTANY MBR (it always
gets clobbered).

---

Mandrake will see your hidden partitions, and will mount them, and
will give you read and write access to them, if you mount them that
way. But it will not do that unless you tell it to, and I cannot say
whether the install process will ask you about it; or you might have
to figure it out for yourself how to do it. But it will not occur
automatically as in Windoze.

There is a "best Linux distro" thread around here or in the Open
Source group, and the advice there on Linux distros is better than
mine. I've used RedHat and SuSE and preferred the latter, but have
no religious convictions about either and don't want to shortchange
those I have not fiddled with.

[bvar22]

6. You are correct.

Linux will indeed SEE partitions hidden in MS Systems.
I booted from the KOPPIX CDROM, and ALL the hidden drives are visible, so , On to Plan B.


I'm curious how handle Mandrake will handle this . I'm going to reformat one of the hidden Primary Partitions. That will leave 2 bootable Primary Partitions (one ACTIVE and one hidden) plus an Empty Primary Partition.

[bvar22]

7. It went surprisingly well.

I deleted a Primary Partition, then booted from the Mandrake Install CDROM.
Mandrake found the Partitions and labeled them correctly (Primary Active, Blank Space, and Hidden Primary Fat32.
Mandrake suggested install to the blank space, which is what I wanted. I did.

The install was (as far as I can tell so far) faultless.
On the reboot, Lilo came up and offered selections for Linux, Windows, and Windows2.

I was able to boot into XP, and using PQBoot I could boot to Me, and doing nothing brings up Mandrake!

Mandrake is invisible from XP and Me, and all the Drive Letters in the logical partitions are as they should be.

I'M A HAPPY PUPPY.
Now all I have to do is learn to use Linux.