🚀 go-pugleaf

Gregory Hore (greghore@elands.hna.com.au) wrote:
: The hda was formatted using Redhat's linux fdisk originally.  When I 
: came to use MS-Dos fdisk, it could only see 500Mb of my 1Gb disk, so 
: I used the (much better) linux fdisk to format three dos type 6 
: partitions.

You got a OLD bios which wont go above 1024 cylinders.
Once boot up linux can recognize more than 1024 cylinders.

: That all worked fine for a few weeks, until a yesterday, when 
: the 'merde' hit the blower.
: 
: 'Missing operating system', 'invalid media descriptor', a partition 
: table that's a mess, all in a millisecond.

Most probably while in DOS and tried to write to cylinders above 1024,
got wrapped around to the beginning, i.e. bye bye MBR, partition info,
boot sector and FATs (File Allocation Table, primary and backup).  If
you are lucky the backup FAT might still be there intact. You might be
able to put in the original partition info (using linux) and MBR and
boot sector (using DOS), copy the backup FAT to the location for the
primary. It is hard to recover without the FATs. Might be able to
recover those in the other partitions.

: I have backups of _most_ of it, but feel that if I could get the 
: partition table specified properly, all might be well again.  I'm 
: reluctant to reformat until it's certain that I've lost the recent 
: work.

If you can recover the files or if you restore from backup, make
sure you use one of those Disk Manager for DOS that can handle
more than 1024 cylinders.

: Very gingerly let NDD onto it, let it reset boot record and media 
: descriptor for hda1, (keeping undo info)  I can now see a very messy 
: directory with silly names and sizes, so either the geometry isn't 
: right, or the disk really is a mess.  Restore.

Primary FAT was over-written. What about the backup FAT?

-- 
David Chia
RMIT University