Manually fixing Nonresident GList on 7200.12

[xsoliman]

This thread is a continuation of the latter half of viewtopic.php?f=1&t=19275
where I was experimenting with the 7200.11 F3 T>m0,2,....... 'reformat' commands ('Leonardo method') on a scrap 2000GB 7200.12 drive, and messed it up further

WARNING - DON’T DO THIS, unless experimenting

I've now stupidly done the same thing on a test 500GB 7200.12 drive
(was playing with STCom tools and pushed the wrong button)

The V40 Nonresident GList is now empty

The V1 list is missing the slips from the Nonresident GList and is showing other (plist) slips at the 'wrong' place
(due to the missing nrglist entries)


HOWEVER

I did record the Nonresident GList entries from earlier when it was working perfectly fine


F3 T>V40
Nonresident GList 5 entries returned
Total entries available: 5
PBA Len Flags Phy Cyl Hd PhySctr SFI
8500 2 0 D 0 7E0 105A60
21E00 1 0 1F 1 5D8 B3B3F
21F00 1 0 1F 1 6D8 D3B70
22000 1 0 1F 1 7D8 F3BB7
22100 1 0 1F 1 8D8 113B9B


So, now the question is how to manually enter these V40 entries
(and force rebuild of V1 list)

Note - Just doing scanning with MHDD and enabling realloc is NOT a way to populate the NRGlist (just puts it on the normal g and alt lists)

I also need to clear out some 'rubbish' from the V4 Reassigned Sectors List
as current reallocation is putting 8500 stuff there (and not just the 2 bad sectors at 8500, but most sectors after there)

Experiments are continuing
but if anyone knows how to manually add to the Nonresident GList, I'd appreciate their advice

Later I will mess it up again and pretend I don't know the necessary Nonresident GList entries to add, and try some 'scan and find bad' techniques to try to locate them and manually add them to the Nonresident GList

[xsoliman]

Well still not found a way to enter explicit NRGL entries

However after doing some more m,0 formats with different parameters via some functions built in to STCom tools for F3 [details to follow later]
the drive is now back fully functional

The strange thing is now has a totally different single NRGL entry

F3 T>V40
Nonresident GList 1 entries returned
Total entries available: 1
PBA Len Flags Phy Cyl Hd PhySctr SFI
1A5793C A05 0 1540 1 0 AB577

and the previous PBA 8500 sector is working fine now

(no V4 Reassigned Sectors either)

Obviously if it had real data on it, that data would now not be 'correct' as the slippage is different

I'll test that in later experiments


Also, the length of the entry in the NRGL seems abnormally high and must be most of the track ?

[xsoliman]

On reflection, I'm not 100% certain that the state of this disk (2 weeks ago) with the 5 Nonresident GList entries
was the original state of the drive after all
The entries look 'unusual' and the V1 user slip list at that point did have something at LBA 1A57xxx even though there was no NRGL (or plist) entry for that.

More than likely I had been messing with the drive for the past few months and messed it up, and don't have a full record of the real original state of the drive, and its a surprise that it was still working in that state

I've 'rebuilt' it again and get the same latest state with a single 1A5793C A05 NRGL entry
and the drive looks good again and reads 100% fine at the sata interface


I've tried 'rebuilding' my bad 2000TB drive again, but that fails to rebuild due to some real disk errors that never allows the 'rebuild' to complete correctly

I will continue the 7200.12 NRGL experiments
and rebuilding of NRGL
including seeing if we can do it without losing data (ie need to rebuild to the exact original slip state which will be very difficult if the original state is not known)

[xsoliman]

For info

The Seagate Momentus 7200.4 (2.5" sata) is an F3 drive with a Nonresident GList

viewtopic.php?f=1&t=18094

[xsoliman]

as is the 2.5" Momentus 5400.6
and 3.5" DiamondMax 23

[xsoliman]

Link to another topic related to similar 7200.12 issues

Seagate 7200.12 “Init SMART Fail” investigations
viewtopic.php?f=13&t=27731

[pepe]

With the very first .11 drive i received around 2008 i had to push myself through this issue, find out why the 'm' command fails and how to do it correctly.
It is funny it was some ST3500820AS drive, which later proved to be far less frequently having NRGlist entries than 2.5" drives (i had 1 or 2 having NRG) but i had such luck with the first drive
There are a couple of ways to achieve the goal, but u really need to work it out.

[NeGrusti]

I have a bit different problem regarding NRG
I delete 35 entries of NRG by editing both copies of FID 035
clear V1, V4, V80 is already empty in my case
cycle the power
Ensure that V1, V4, V40, V80 is empty
recalculate translator m0,6,1,,,,,2 - excluding P-List for this experiment
And I see my 35 entries appear in V1! Where do they come from?
m0,6,0,,,,,22 yelds the same results.
Must be some other table holding my 35 entries, where?