Hard disks file.missing/gone without a way to.know?

[kidmid99]

Hello
Ive had 2 hdd with important data whice i didnt backup for 10 years.
One hdd is almost full of capacity .
The other has 123 gb free space
Since i got so many data on it,i cant know what was lost ,missing
My question is .
If i use disk check for bad sectors ,can i tell if any file got missing?
If its find no corruptions/bad sectors.
Does this means i havent lost any files?

And when i press properties to check disk space .
Can i safely trust its showing me the right bits and data on the external hdd?
Thank you

 

[stdragon]

It's what I call the "unknown unknowns". As in, you don't know what you're missing, and when it went missing. Essentially, you're chasing rainbows.

The best you can hope for is to scan and report back any files that can be un-deleted. Try Recuva at the link below.

https://www.ccleaner.com/recuva

 

[Peter Martin]

i would resolve to back stuff up to the cloud so your devices can all blow up and you don't lose data. if you have 'lots of data' that you never look at or use or review, should you even hold onto it? ask yourself some questions. little needs to be backed up, docs, media, pics, that's it. everything else should be downloadable again.

 

[rgd1101]

If the drive is failing. backup first, or you might lose it all

 

[kidmid99]

All my hdd are backup but some i did backup after years .
Some usb pen with virus cant be backup till i use virtual box to.isolate it.since i dont trust anti virus maleware to find for sure the infections.
Anyway the data is 1 year of photography work.that i spendes 8 hours a day to work on my photos.
But since i have so muxh files i dont remmber or cant follow it.ni one can.without a method.
My question is : how can i know ?
Should i even try recover ? Isnt recover will find all the data inculded the hdd data and than i will need to.spend 1000000 hours just to.chexk each file compared to the ones in hdd?
There is a method to check if file were gone from my hdd ?
Since after 8 years the precentage of corruption or missing files can be common no?

 

[kidmid99]

Peter
Im asking if there is a way to check for file missing .or deleted data since this can accure if the magnets on the hdd lost its powers and bytes of data were lost.
If enought bytes that create a file was gone .does the file stille visable as 100% corrupted in the folder ,or does the file.just gone?
Also file system can be corrupted aswell no? So properites of the hdd can be mislead?
I have around 1 milion photos of 10 years of photography .thats my life but i was enjoying taking pictures and didnt do backups ,i wasnt aware of hdd failure,

 

[stdragon]

If you're trying to reconcile difference and changes of files between two difference data sets (two drives), the best program I know is called Beyond Compare. Note, this is NOT a recovery program. It's only a tool. Only you can decide which files supersedes the other as this would be a manual reconciliation process. Link below.

https://www.scootersoftware.com/features.php

 

[Peter Martin]

there are data recovery services that cost a lot. how much is that data worth?
https://www.salvagedata.com/

 

[kidmid99]

@stdragon
If i have two.drivea.than i can check propertiea of.each and sees if its the same.
No, im trying to figure in my 10 years old drive ehoce files got misisng(i didnt had backup)

 

[kidmid99]

@peter it cost a lot yeas and there ia no reason to do so if i dont even know if i lost any file.
So in trying to figure out if.i had hdd failure /corruption pr missing file.
So im.asking for methods to do so.
Using recovery programs will mean i need to.look and compare each file if it exist . And that can take infinite hours

 

[USAFRet]

You've been using a PC for a decade or more, and you never realized that electronics can fail?

------------------------------------>

 

[stdragon]

@stdragon
If i have two.drivea.than i can check propertiea of.each and sees if its the same.
No, im trying to figure in my 10 years old drive ehoce files got misisng(i didnt had backup)

No idea. If you run a chkdsk command against both drives (assuming they're Windows NTFS volumes), and it reports back no errors - yeah, you should be ok.

Now, if you deleted a file or had a virus randomly wack files from them...no way. Couldn't tell you. Good luck

 

[kidmid99]

@usafret i thought it wil be okay

 

[kidmid99]

@strdragon
One of the drive after 10 hours of disk check found no issuses and all was good.
Thats an hdd that is alive 10 years and 8+ years without being powerdon.
I.wonder how long it will last and.how come files didnt decay since magnetic failure.

 

[stdragon]

"Decay" = Data degradation. AKA "Bit Rot"

https://en.m.wikipedia.org/wiki/Data_degradation

Standard CDR media will breakdown in less than 10 years due to film oxidization. There is CRC in the bit stream, but even the rot can get so bad data is lost forever and can't be corrected; either in whole or in part.

Hard drives left powered off for years at a time can actually have their heads "welded" to the disk. It's rare, but can happen, or so I've been informed.

Regardless, have your data copied in three places and in different physical formats. Never put all your eggs in one basket.

 

[kidmid99]

Please be more clear.
Please dont talk about backups i allready know that.(but i didnt know till latley that hdd are ao fragile)
So file decay can hepend if the magnets lose its power no? Since than bytes infornation start to dispear and thab the file can get decay aka currpted aka gone/missing..

 

[Peter Martin]

no

 

[stdragon]

Please be more clear.
Please dont talk about backups i allready know that.(but i didnt know till latley that hdd are ao fragile)
So file decay can hepend if the magnets lose its power no? Since than bytes infornation start to dispear and thab the file can get decay aka currpted aka gone/missing..

All data is stored in ones and zeros (1 an 0), hence the term 'binary'. Those 1's and 0's are interpolated as such based on the media they're recorded on. If it's CDR disks, you see them as pits and landings, or dots and dashes. Basically, a really long bar code that's written around the disk in tracks. With Hard Disks and tape, the magnetic poles go back and forth on the media as it travels under the read/write head.

That all said, nothing is perfect. Minute errors do and will occur when recording data to media. But the engineers and computer scientists know that when creating these storage technologies. It's because of this, that media has CRC (cyclic redundancy check) method used to identify and correct for errors. With Hard Disks, the encoding to employ CRC is in the form of MFM (modified frequency modulation).

TLDR: Basically, CRC can only assist so far. If the media has become too degraded or damage, it becomes impossible to reconstruct the data. Also, Hard Drives are electro-mechanical devices. It's not a matter of if, it's WHEN a drive failure will occur. And fail it will.

So again, BACK UP YOUR DATA. Never assume any storage media is infallible; because it's not.

 

[stdragon]

If you want your data to last at least 100 years in a vault, it's best to look at archival CDR media. It's more expensive because it's made of gold (AU). Gold is used because it's a noble metal that wont oxidize.

http://www.verbatim.com/prod/optical-media/cd/archival-grade-gold-cd-r/ultralife/

M-DISC 25GB Blu-ray Permanent Data Archival / Backup Blank Disc Media - 15 Pack Cake Box - 1,000 year life
by Millenniata Inc.
Link: http://a.co/hKlGRbO

Flash drives can retain data for up to 10 years unplugged.

 

[4745454b]

MERGED QUESTION
Question from kidmid99 : "Also what id"

Again .
How can i check if there was an error or if data on the magnet was lost?
There is a eay to check it?
Isnt it for sure that hdd will lose its magnetic data if u dont overwrtie all the files again to the hdd and therebye restore magnetix life cycle?

There is high chance my hdd lost bytes since charge on the magnets were off

What, try rephrasing the question in English please?

 

[Peter Martin]

quick answer to OP question, There is NO way to know if you lost something. get over it. hardware fails.

 

[kidmid99]

@peter

"Get over it"
No ty you.
Its important for me to know what i can do.
Period the backup time.

I can do.recoveru.for.example and compare each file ffound(this method will take me.ages)
Ill die before finishin it.but ita way.
There can be probably more ways from geniouses at computers.


@stdragon
This disks are 25 gb
Also
There is sony new storage media
That last 50 yeara with 3 tb capacity but it cost 5000$
So ill buy it when price will drop.

Also about crc.,can u explain or give.me.link how to use it?

Also even backup can fail .
U saying hdd are electronics and its destiny is to fail.
So ny long option would be sony archive disks(can last 50 years) it cost 5000$ for the burner

 

[Peter Martin]

sorry, there isn't any other way to know if data is missing unless you look at. Can you program AI to do it? I doubt many can, nor have the inclination to, and, if they could, would probably charge you even MORE than normal data recovery. I would recover it with data recovery and start the pruning process which you have been letting go for the last decade by your own admission. Plus, you never backed up so there's that. Your best option is to recover and do your manual analysis.

 

[kidmid99]

@peter
Thank you.what is pruning?
All my 10 hdd are fully backedup
I didbt back up.cause i never had any clue hdd are sensetive do data loss.i thought my data would be fine as it is.
I did not know about data missing/curroption nor anything else.
Also i had files i wanted to.edit before backingup. Whice i didnt do for many years at the end.
I admit i was naive,mybe i am stille am in some areas at computing that i will learn
Idk i just did a mistake.
If the recovery would show me.the files names than its great but if not. Tha manully comparing images or videos would take me 100 years

 

[kidmid99]

@peter
There is a methos i use now
I do properties and print screen than save it in paint.i have full control of the bytes stored. Each and every byte
Now thia to know exactly if something deleted.curropted or so
Eveen if one byte is missing i can know