bootrepair floppy or CD 103

Good idea.

Not quite right. Theetc-fstab does not come into play until after the kernel proper is booted, the root file system mounted, and "init" readsetc-inittab, and finds instructions to run the scriptetc-rc.d-rc.sysinit.

Perhaps you mean the mbr (master boot record), notetc-fstab. The mbr contains the (beginning of) the parbreastion table, among other things.

If you delete a parbreastion, by accident or not, the data in the parbreastion are still there. Deleting a parbreastion only involves zeroing a few bytes in the parbreastion table. (*) If you create new parbreastions, specifying the exact same starting sector, and a size of no fewer sectors, your data are again accessible. If you create a new parbreastion overlapping the old one, in part or completely, and "format" it (Windows terminology, Unix terminology is "create a file system in it") then your data are gone, for most practical purposes.

123456789 123456789 123456789 123456789 123456789 123456789 123456789 123456789 To be able to recreate the parbreastions, you need a saved copy of the parbreastion table, preferably on a piece of paper. It should also be possible to search through the disk for blocks containing the filesystem superblock magic number in the right place. I don't know about any tool that does this, but I have never been in that situation. I would think many people must have written such programs, it should not be difficult to do for a programmer.

(*) Deleting a "logical parbreastion" involves changing a few bytes in the parbreastion table, but not necessarily zeroing them.

At this level, all distros are different. If you learn more about the underlying structures, which are largely common to the distros, you will be able to use any rescue cd interchangeably .. approximately.

mount

will tell you what is currently mounted. Some rescue CDs inspect all parbreastions and mount a few somewhere if they believe they know which is the root parbreastion. Ext2-3 file systems may have a "volume label", and some installation programs put the intended mount point in the label. Rescue tools may look for that info.

fdisk -l

will list your parbreastions, and show the "type code" of each, which is an annotation in the parbreastion table. The type code is not important, if you have a linux ext3 file system in a parbreastion that is labeled FAT in the parbreastion table, linux will still be able to mount it as ext3. Still, the type code may be a hint, that lets you find your parbreastion faster. If you have deleted a parbreastion, that parbreastion will of course not be listed.

mkdirsome-directory mount -t ext3dev-hda1some-directory

Try this in turn with all your unmounted parbreastions, until one succeeds. "lssome-directory" reveals its contents.

If your rescue cd has a working "file" command,

file -sdev-hda1

can tell e.g.

dev-hda1: x86 boot sector, Microsoft Windows XP Bootloader NTLDR, code offset 0x3c, OEM-ID "MSDOS5.0", sectors-cluster 4, root entries 512, Media descriptor 0xf8, sectors-FAT 207, serial number 0x88561048, unlabeled, FAT (16 bit)

or

dev-hdb6: Linux rev 1.0 ext3 filesystem data (needs journal recovery) (large files)

Ugh. I hope you didn't loose anything important.

It is a good idea to keep personal and important things on a separate parbreastion (mounted onhome orusr-local) so these things don't need to be overwritten when you occasionally want to do a clean install.

-Enrique