Wow, what a great explanation. I have read through it, but am going to do another to make sure it's all taken in. Thanks.
--- Mike McCarty <[EMAIL PROTECTED]> wrote: > Jeremy Merritt wrote: > > I have been having a problem getting my GRUB > > bootloader to return on boot. No matter what I do, > it > > keeps going to XP. I consulted with other people > on > > this list and got some good input. But have run > into a > > dead end again. Can someone analyze these steps > and > > tell me what I'm doing wrong, or what I need to do > to > > get the GRUB menu to return the way it was when I > > first installed Debian: > > > > Steps so far: > > > > 1. Boot up with live CD (Knoppix) > > 2. Activate shell and go root > > 3. Mount /dev/hda5 as /mnt/hda5 > > 4. chroot /mnt/hda5 /bin/bash > > 5. grub-install /dev/hda5 -- Reports successful > > install but no results on bootup > > You installed GRUB as the boot record (BR) of one > of your partitions (/dev/hda5). This will work fine, > but it is > not what the BIOS will load. > > I think you need a little more information about how > boot is accomplished on IBM PC style computers. If > you get that, then I think things will be much more > clear. So, here is a brief tutorial on disc > partitioning > and how boot proceeds. > > Those who are familiar with this may either skip the > rest of this message, or use it as a review, or > criticize it for errors or omissions. > > Discs, to be used, must be formatted. The formatting > takes place in levels. The lowest level (sometimes > called low-level format) places tracks and sectors > on > each surface usable on the disc. Modern hard discs > reserve > one surface to hold tracking information alone, no > data. Low-level formatting should not be done on > modern > hard discs except at the factory. Those of us who > used to > use MFM and RLL discs are glad for that. > > (Floppy discs have all three levels done at once > by a single program, usually. This causes some > confusion. The levels of formatting are actually > done in passes even for floppies.) > > At the second level of formatting, the surface is > divided into > partitions (floppy discs have only one partition, so > they > have no partitioning to be done). Traditionally, the > first > record on the disc, the Master Boot Record (MBR) > contains > two parts: a small bootstrap program and a Partition > Table > (PT). Some consider the PT to be separate from the > MBR. > Also, traditionally, there may only be four (4) > partitions defined. > However, as time went by discs grew larger, and a > percieved > need for more partitions grew as well. So the > concept of > a Primary Partition and an Extended Partition was > developed. > There could be only four (4) Primary Partitions, but > only one (1) Extended Partition. If an Extended > Partition > existed, it used up one of the entries, so only up > to three > (3) Primary Partitions could then be defined. The PT > uses > physical addresses (head, track [or cylinder], and > sector). > > Within the Extended Partition, Logical Partitions > (also > called Logical Discs or Volumes) could be created. > Primary > Partitions also contain Volumes, but only one per > partition. > > Each Partition has a type (OS, more or less) and a > status. > The status could be either Bootable (also called > Active) or > non-bootable (Inactive). Only up to one (1) > partition may be in > an Active state, and if so, it must be a Primary > Partition. > > A floppy disc is a single Volume, hard discs > may have up to one Volume per Primary Partition, and > any number of Volumes (logical partitions or logical > discs) in an extended partition. Each Volume has > a Boot Record (BR) also called BIOS Parameter Block > (BPB). > Technically, the BPB is actually a part of the BR, > in > somewhat the same way the PT is part of the MBR. > > The BR contains a description of the logical layout > of the Volume, > like how many reserved sectors there are before the > data area, > how many logical sectors there are, etc. The BR uses > logical disc > addressing (logical sector number). > > The top level of format is the File System (FS). The > file system uses allocatable units for addressing. > Exactly > what an allocatable unit is depends on what FS is > being > used. Usually the FS presents an Application > Programming > Interface (API) which uses File Addressing > (directories, > files, and records within file). > > > > > fdisk -l information (hda5=Mandrake, hdb2=Debian, > > system is booting from hda1=XP): > > > > Disk /dev/hda: 40.0 GB, 40020664320 bytes > > This is your first disc. > > > 255 heads, 63 sectors/track, 4865 cylinders > > Units = cylinders of 16065 * 512 = 8225280 bytes > > > > Device Boot Start End Blocks Id System > > /dev/hda1 * 1 2433 19543041 7 HPFS/NTFS > > Here is your primary partition which is active. > > > /dev/hda2 2434 4865 19535040 5 Extended > > This is your extended partition. > > > /dev/hda5 2434 3197 6136798+ 83 Linux > > /dev/hda6 3198 3337 1124518+ 82 Linux swap > > /dev/hda7 3338 4865 12273628+ 83 Linux > > These are volumes inside your extended partition. > Each of them may be treated as a partition. > > > > Disk /dev/hdb: 61.4 GB, 61492838400 bytes > > This is your second disc. > > > 255 heads, 63 sectors/track, 7476 cylinders > > Units = cylinders of 16065 * 512 = 8225280 bytes > > > > Device Boot Start End Blocks Id System > > /dev/hdb1 1 3188 25607578+ c W95 FAT32 (LBA) > > This is a primary partition, not bootable. > (LBA = Linear Block Addressing, which means > that your BIOS is translating logical disc > addresses [sector number only] into physical > addresses [head, cylinder, sector] for you.) > > > /dev/hdb2 * 3189 7298 33013575 83 Linux > > This is a primary partition, which is active. > > > /dev/hdb3 7299 7476 1429785 5 Extended > > This is an extended partition. > > > /dev/hdb5 7299 7476 1429753+ 82 Linux swap > > This is a logical volume inside your extended > partition. > > > > > Disk /dev/hdd: 30.0 GB, 30020272128 bytes > > This is your fourth disc. (Where is 3? Possibly > your CD reader.) > > > 255 heads, 63 sectors/track, 3649 cylinders > > Units = cylinders of 16065 * 512 = 8225280 bytes > > > > Device Boot Start End Blocks Id System > > /dev/hdd1 * 1 3649 29310561 83 Linux > === message truncated === __________________________________ Yahoo! Mail - PC Magazine Editors' Choice 2005 http://mail.yahoo.com -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]