Data recovery and disk repair questions and discussions related to old-fashioned SATA, SAS, SCSI, IDE, MFM hard drives - any type of storage device that has moving parts
June 26th, 2019, 16:35
Hi guys,
How do you deal with surface damages like these?
Its a Seagate Barracuda 2TB.
Do you even try to swap HSA?
https://ibb.co/NY6Q6Xs
June 26th, 2019, 17:06
You can try, it may be only the top platter which is damaged and you may get lucky and get the client critical files if they are small. If you remove the heads you can inspect them under a microscope and look for damage to H0. If it is damaged, or there is debris around the slider, there is little point in doing a head swap. In situations like this I always charge the client an 'attempt fee' to cover parts and a little labor and most importantly manage their expectation that recovery is very unlikely.
June 26th, 2019, 18:09
If the damage is close to the center, as it seems to be here, isn't it possible to get a decent recovery rate by imaging forward (from the outer edge to the center) up until the begining of the bad area, then (optionally) imaging backward up until the end of the bad area ? Why is a damaged head 0 particularly bad for the overall odds of a successful recovery ?
I thought that dedicated data recovery labs could get something out of HDDs which suffered the most extreme kind of damage, like fire or flood, so it seems surprising that just one little groove is enough to thwart the efforts of seasoned experts in this field...
June 26th, 2019, 18:26
In order to get a drive to read, the hard drives system area needs to be read as it contains a lot of unique files specific to that drive. If those files cannot be read then there is no access to data, forwards or backwards. For this type of damage to occur, the drive has been spun for an extended length of time, probably be the client wanting the drive to magically start reading. All that time the drive is trying to read those system area files while damaging the media surface. If H0 is damaged/or has debris, then this is indicative of all the platters being damaged as well as the top one.
It may be a 'little groove' to the untrained eye. But as the heads travel 3 millionth of an inch (ish) over the platter surface, the tiniest groove can have a significant effect on the heads. Its like driving your car at a curb and expecting to come out the other side with the wheels on. Fire and water damaged drives are often recoverable as the damage can be cleaned from the drive and the SA read. Physical damage to the media is a whole lot harder (if not impossible) to overcome.
June 27th, 2019, 2:12
+1 ddrecovery
June 27th, 2019, 7:25
Since this is a Seagate, it looks like its the SA that is damaged.
Thanks for all your inputs!
June 27th, 2019, 9:00
you should check all heads under microscope. if other heads haven't debris (specially h0)try to swap the heads. sometimes firmware on outer track. if these ok, you should make a manual stoper for head stack, preventing head damage.this is not easy as we say. try to carefully.
June 27th, 2019, 12:43
In order to get a drive to read, the hard drive's system area needs to be read as it contains a lot of unique files specific to that drive. If those files cannot be read then there is no access to data, forwards or backwards. For this type of damage to occur, the drive has been spun for an extended length of time, probably b[y] the client wanting the drive to magically start reading. All that time the drive is trying to read those system area files while damaging the media surface. If H0 is damaged /or has debris, then this is indicative of all the platters being damaged as well as the top one.
It may be a 'little groove' to the untrained eye. But as the heads travel 3 millionth of an inch (ish) over the platter surface, the tiniest groove can have a significant effect on the heads. Its like driving your car at a curb and expecting to come out the other side with the wheels on. Fire and water damaged drives are often recoverable as the damage can be cleaned from the drive and the SA read. Physical damage to the media is a whole lot harder (if not impossible) to overcome.
Alright, thanks for the detailed explanation.
But I thought that the system area contained a
copy of the data also present in a ROM chip or embedded within the main chip unit on the circuit board (or the other way around : that the PCB contained a copy of the data present in the SA). So (sorry in advance if it's completely silly), couldn't there be a method whereby the relevant contents of the ROM would be dumped from the PCB to the system area of a similar drive, and then a “live PCB swap” could bypass the damaged system area, allowing to read the contents of the undamaged portion of the user area on the defective drive ?
June 27th, 2019, 13:07
abolibibelot wrote:Alright, thanks for the detailed explanation.
But I thought that the system area contained a copy of the data also present in a ROM chip or embedded within the main chip unit on the circuit board (or the other way around : that the PCB contained a copy of the data present in the SA). So (sorry in advance if it's completely silly), couldn't there be a method whereby the relevant contents of the ROM would be dumped from the PCB to the system area of a similar drive, and then a “live PCB swap” could bypass the damaged system area, allowing to read the contents of the undamaged portion of the user area on the defective drive ?
The firmware in the ROM and the firmware in the SA are very different. The ROM firmware is there to get the drive to initially boot and is very small (KB's). The firmware on the drive itself is many GB's. In PC terms think of the ROM as the BIOS and the FW as the OS. Both do different jobs and are certainly not interchangeable. WD's do in fact keep a copy of the ROM in the SA, where Seagate do not. All modern SA's have unique files/tables created by the drive, ie G-Lists. Without reading these unique files there is no access to user data, even if every other SA file has been read.
As far as a 'hot swap' is concerned, this is only possible if the main part of the SA either has, or can be read. You copy the patient drives critical SA modules (which may be an amalgamation of SA files from several heads to make one good set of files) to a donor drive. Boot that drive up (with some manipulation) so it has read the patients critical SA files. Put the drive to sleep and swap the board to the patient and wake it up. This works with limited drive models and families. HOWEVER, to get this to work, you have to have read the critical SA files from the patient. So in the case here, that is probably not possible.
July 17th, 2019, 13:42
it can be done if it's all the damage you showed on the pic.
pepe
July 17th, 2019, 15:17
Love this video from Erkin:
https://www.youtube.com/watch?v=gmCOTz0YVfANever tried something like this...
July 17th, 2019, 16:05
yeah, he is praised pretty much for it

I think i could be famous making videos of tricky recoveries too

However, this method does not work for this patient, it is a bit more complex. Quite a bit...
pepe
July 17th, 2019, 17:06
If you have time for experiments.... yourself.
My opinion is that is to waste time, if you get something will be very partial and what you can NOT recover will always be the most important for the client, personally ... put stamp and send it back
July 17th, 2019, 17:49
some years ago I loved these cases, I was 3-4 days trying to recover the data, losing money in many cases, just for the fact of being able to recover something, and I said "well" I managed to recover something ..... then you communicated with the client and reluctantly accepted the recovery, or not, based, as always, that what could NOT be recovered was the most important thing (as if I was the culprit of losing their data)
nowadays, if I open a drive in those conditions.... it doesn't take me even 10 seconds to close it and put the seal back on it.....
July 19th, 2019, 3:05
yes, clients are a problem sometimes, but it also depends on the communication. They need to understand we can recover what's left after the disaster and not recreate their data out of nothing. I used to tell a parable: if you manage to get your leg cut by the train and some genius doctor can fit it back so that you can walk, you are happy with it. You won't be able to run most probably or win competitions but being able to take care of yourself in a decent way is far better than living without that limb.
On the other hand, yes, more money can be made on easy jobs... But where's the challenge then?
pepe
July 19th, 2019, 5:28
pepe wrote:yes, clients are a problem sometimes, but it also depends on the communication. They need to understand we can recover what's left after the disaster and not recreate their data out of nothing. I used to tell a parable: if you manage to get your leg cut by the train and some genius doctor can fit it back so that you can walk, you are happy with it. You won't be able to run most probably or win competitions but being able to take care of yourself in a decent way is far better than living without that limb.
On the other hand, yes, more money can be made on easy jobs... But where's the challenge then?
pepe
I like that parable
July 19th, 2019, 6:41
pepe wrote:I used to tell a parable: if you manage to get your leg cut by the train and some genius doctor can fit it back so that you can walk, you are happy with it. You won't be able to run most probably or win competitions but being able to take care of yourself in a decent way is far better than living without that limb.
On the other hand, yes, more money can be made on easy jobs... But where's the challenge then?
pepe
hahaha. i like it
July 20th, 2019, 12:09
pepe wrote: On the other hand, yes, more money can be made on easy jobs... But where's the challenge then pepe
Pepe, OK... How to rebuild an F3 rom is no longer any challenge for you...... I pass you all cases of severe damage to surfaces and you tell me how to rebuild an F3 Rom.......
July 20th, 2019, 12:47
How to rebuild an F3 rom is no longer any challenge for you
unfortunately it is still a challenge on new families...
July 20th, 2019, 13:20
Well, I wouldn't ask you to give me all the models, I don't want to abuse

... maybe a couple of models...? (I would pay for the beers)
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