A question for enlightenment from anyone who knows about DOS _and_ Linux, and of what happens with the MBR; I didn't get much of that from the so-called Linux "newbie" list:
With a new Linux (Mandrake) install I'd overwritten the MBR on the the primary partition of the first HD, and the DOS partition there is no longer accessible - it's still there, as the disk partinioning had not been changed, and only the (unchanged) linux ext2-partitions had been re-formatted; looking from the (new) Linux, the DOS-parition shows up fully and as it was. One of the "basic" books(*) has the following description, but typically does _not_ explain you what happens when you follow it: " LILO saves backup copies of your original boot record in the files " /boot/boot.0300 (for IDE drives) ... These files contain the MBR of " the drive before LILO was installed. You can use the _dd_ command to " replace the boot record on the drive with this backup copy. " For example: " dd if=/boot/boot.0300 of=/dev/hada bs=446 count=1 " copies the first 446 bytes of the files /boot/boot.0300 to /dev/hda. " Even though the files are 512 bytes in size, only the first 446 bytes " should be copied back to the MBR." And indeed, "/boot/boot.0300" is duely there in that new install. Now IIRR, the MBR contains an address where to jump to - not a filename or a thing like that - and where the real process of booting up would start; thus in the case of this install, the various alternatives defined with LILO. What happens then when I do that rewriting - will the _whole_ setup of the system possibly become inaccessible (and not only the DOS partition) ? (Because the "old" MBR would jump into nirwana - or would the new install, as it uses exactly the same fundamental arrangement, have the new Linux boot-start precisely there where the former such was, i.e. in the unchanged, small, "/boot" partition on "hda" ?) And what happened before, when I stupidly followed the (otherwise in regard to partitioning quite transparent and well working) Mdk-install ? (Only it gives an ambiguously worded "recommendation" for _where_ to write the dang MBR finally; and I did the typical newbie error in trusting it and acting inattentive - by now I wonder how come I did not do that error n-times before: never _had_ that trouble with numerous installs.) Is the _whole_ DOS partition table gone, or only the "hook" in the MBR where to read it ? (The latter seems more logical, as the well booting Linux _does_ read an apparently unchanged and integer DOS-partition.) Or may there have been still another error, for instance, in that I just did _not_ do anything about the DOS partition in the install sequence ? Mdk has a nice visualisation of the existing, found partitions of the HD - and I just didn't do _anything_ with the clearly indicated DOS partition there, probably (cannot remember exactly) just defined it there to be mounted as "/dos-c". (Must have been this, because I remember to have changed later the filesystem-type in "fstab" from "vfat" to "msdos". There's an indeed conventional, 16-bit, DR_DOS there.) Secondly - what happens if I redo the DOS install on the (still existing) first/primary HD partition: could I still alternatively boot (into) the Linux installed ? BTW, there's no problem of risking data loss as all _data_ files from both systems had been saved elsewhere; it's the prospect of a very time consuming and boring re-installation of both "systems" (which both had been well tuned, even in the meantime the newly installed Linux there.) Some primary school teaching appreciated... // Heimo Claasen // <hammer at revobild dot net> // Brussels 2003-08-02 The WebPlace of ReRead - and much to read ==> http://www.revobild.net (*) O'Reilly's "Running Linux"; that book, as well as some others widely considered basic and fundamental, tell you how "powerful" everything in Linux is. But don't ask for any explanation that would make you understand how and why - be a good child, follow the paternalistic prescriptions and certainly never ever look behind a door which is declared forbidden. Argh. -hc To unsubscribe from SURVPC send a message to [EMAIL PROTECTED] with unsubscribe SURVPC in the body of the message. Also, trim this footer from any quoted replies. More info can be found at; http://www.softcon.com/archives/SURVPC.html
