I've got win98 and fc4 sharing the single 20G hdd on my old pII machine. I no longer want the win98 boot (who would), but worry that by deleting it (by fdisk etc) I will lose the MBR.
Since this is a difficult one to research, I wonder if anyone has any hints/tips and gotchas ?

I guess that I could just delete all the filesystem junk and run it as vfat, but this is not very elegant (IMHO). I'd rather convert it properly to ext3.

Any help appreciated.

You should just be able to format it from within FC4. Just do a mkfs.ext3 /dev/hda1 as root (assuming /dev/hda1 is your win98 partition, of course). This should leave the MBR alone.

Are you booting with grub??? If you are windows isn't on the MBR, do as pljvaldez says and there won't be a problem.
If you're using some other boot loader, you may be better off reinstalling grub to the MBR anyway.
you can do this from a boot floppy, look at "info grub" section 3.1 tells you how to make the floppy, then how to use this to install grub to the MBR. Or you're install #1 CD or DVD

I have run mkfs.ext3 /dev/hda1 and this worked okay and I checked that I can still boot into FC4 (which I can). MBR is fine!

Good advice guys : thanks :-)

However : you should have told me to stop right there!!

I have now installed FC5 onto hda1 and that install seems to have gone okay (it took a while though) - BUT - for some reason I have a problem getting FC5 to boot as _i_ expected it should.

I have installed FC5 without re-installing grub and have manually edited (hd0,5)/boot/grub/grub.conf to add the init & vmlinuz for FC5. The problem is that root (hd0,1) does not work and I have to specify root (hd0,0) for FC5 to boot. (When I specify root (hd0,1) , it errors with "unrecognised file system"). I don't understand why (hd0,0) works.

So - after booting (successfuly) with (hd0,0) - when I then try to mount /dev/hda5 (my FC4 / mount point) I find that this is not possible - there's a filesystem error which by now I'm too lazy to replicate so that I can paste it here.

There seems to be some conflict between FC4 & FC5. But I think I may have got something wrong maybe.

Or should I just watch telly and stop all this?

The reason you need (hd0,0) is that you installed FC5 to /dev/hda1, which is (hd0,0) to grub (grub counts from zero so hda is hd0 and partition 1 is partition 0). (hd0,1) corresponds to /dev/hda2. So that's the way it should be.

What is the output of fdisk -l? That might tell you why its upchucking. When mounting /dev/hda5, you need to specify the filesystem type.

Thanks. You're right, and I'm tired. hda5 is - of course - my /boot partition of the FC4 installation.

Thanks again, pljvaldez. Sorry I'm being an idiot.

[root@hathor ~]# fdisk -l

Disk /dev/hda: 20.4 GB, 20496236544 bytes
255 heads, 63 sectors/track, 2491 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/hda1 * 1 1246 10008463+ 83 Linux
/dev/hda2 1247 2491 10000462+ f W95 Ext'd (LBA)
/dev/hda5 1247 1259 104391 83 Linux
/dev/hda6 1260 2465 9687163+ 83 Linux
/dev/hda7 2466 2490 200781 82 Linux swap / Solaris