🚀 go-pugleaf

Colleagues, I have the misfortune to have taken Linux -off- my 
system for a large-ish and extremely important conservation project, 
the NSW government 'Resource and Conservation Assessment Commission', 
using GIS and scads of data in tables, for which the other 
participants are using Dos & Win311 - so must I.

So the posting isn't exactly Linux, but very close ;-)

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.

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.

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.

Perhaps some kind soul can explain to me the mysteries of drive 
mappings, and maybe there's even a way I can find the beginning of 
the two root directories and translate them into partition table 
specifications.  (searching out characteristic strings using NU?)

Email responses to <greghore@elands.hna.com.au> will see the 
successful advisor blessed and rewarded with a case of beer, ono.

Yours in eager, and rather urgent expectation.

Greg Hore <greghore@elands.hna.com.au>
                                                       

Here follows a (reverse) chronology of events around loss of 
partition table on 5x86 hda. Most recent events on top.  Dedicated saints 
will read from the bottom up!
===================
31-may-1996

Call for more experienced advice  ;-)

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.

Using MS-Dos fdisk, find operating system 'unknown' as before.  Set 
partn 1 bootable, no go, restore.

Linux fdisk now sees geometry as 96, 62, 356 ! Reset as table below. 
MS-Dos fdisk now only sees 128Mb, make one partition anyway, just to 
'get in', no go. Restore

Enter this 'artificial' geometry into CMOS, no change.  Restore.

Drives C:, D: and E: present but 'invalid media type'.
 and dos fdisk 'unknown' operating system.

Linux fdisk forces this drive geometry, attempts to change
 it seem to be ignored? Hda is actually 2105,16,63)

Linux fdisk (V)erify partn. table points out hda3 1024/1035 overlap,
 probably due to geometry mapping?


(P)rint partition table, as reset
===
Disk /dev/hda: 32 heads, 62 sectors, 1069 cylinders
Units = cylinders of 1984 * 512 bytes

/dev/hda1	*	1	1	517	512833	6	DOS 16 bit >=32M
	2		518	518	1034	512864	6	"
	3		1024	1035	1069	34720	6	"
===

Use Linux fdisk to delete existing nonsense partitions,
 remake as before (+500M, +500M, remainder. all type 6)

Check Linux fdisk drive geometry, it has been reset back to the 
virtual mappings by fdisk (?)

Fdisk or something, has remapped the drive geometry.
 Reset cyl, head & sector numbers as in CMOS, no go.

***
Linux fdisk shows part. table a complete mess.  No sense at all, odd 
letters and great long strings of numbers.
***
30-may-1996 Go home and sleep on it!
***
On reboot, 'missing operating system'
***
Edit filespec in config.sys & autoexec.bat to remove \fusionlx

Reboot OK but no cdrom (because old path specified)

Copied mscdex from original installation into root
 probably no need, maybe even distastrous.  It's a
 little larger, a little older than the one in \dos
Copied into config.sys
 devicehigh=c:\fusionlx\tslcdr.sys /d:mvcd001 /r
 devicehigh=c:\fusionlx\mvsound.sys d:3 q:10 s:1,220,1,3 m:0 j:1
Copied into autoexec.bat to enable cdrom
 lh c:\fusionlx\mscdex.exe /d:mvcd001 /m:10 /v

Works fine for several weeks, original screen-freeze hiccups ceased 
when 'power management' disabled.

MS-Dos format C:, D:

MS-Dos fdisk sees only 500Mb, so partition with Linux fdisk (type 6, dos)
 but didn't _write down_ the drive geometry and partition details :-((

Fit hda Maxtor 1036Mb drive into 5x86, 133MHz ($370!) card from 
David Reid Electronics, York St.  On board hdd controller.

Original use of hda with Linux OK, now need to use whole drive for big
 GIS project under DOS.

EVENTS START HERE AND READ UPWARDS THROUGH TIME.

=====