USB dock external 4tb Seagate hard drive corrupted partition; too much data

[woodspire]

Hi.

I have a big problem and I hope someone at anandtech will be able to help me (maybe even write an article about it).

I have 6 hard drives from 200gb up to 1tb and I wanted to consolidate all my data on 1 4tb hard drive.

I have an old PC, nf4-sli motherboard (amd) and I have a new sony laptop.

I bought a seagate 4tb 3.5in hard drive.

I have an external usb dock: http://aluratek.com/esata-usb-2-0-sata-hard-drive-docking-enclosure

When I used the usb dock and the sony laptop (via usb) to create a partition on the hard drive, It showed less than 3.6tb (something like 768gb). So I used my old PC (got the nf4 controller and a silicon image 3114 in it) to partition and format the hard drive.

I read on anandtech that we need to format the partition as GPT, not MBR if we want to have one partition that will cover the whole drive. I did it and it worked (did low format and it took 30 hours!)

Then, I plugged the newly formatted hard drive in the usb dock and now, it saw 3.6tb of free space.

I than started moving the data of the other hard drive (with another usb dock) to this new drive.

Remember that it is not a bootable drive and that I have 1 partition for the whole drive.

When I got to 1.4tb of free space left, something weird started to happen. Windows (8) told me to restart to fix a corruption in my hard drive. Also, some folder were no longer accessible (problem IO access). I did a restart and then windows asked me if I want to format the hard drive !

I have 95% of all my data on that drive and now I cannot even see the folders !

After some reading, I understood that my external usb dock might not support a partition bigger than 3tb, even if it display more than that !

I taught that formatting the hard drive on another PC fixed that problem.

What happen (what I believe) is that the usb dock wrap around the space on my hard drive and started writting data at the beginning, overwriting the partition table and the first files put on the drive.

For now, I would really like to:
- fix the problem and get back to filling the drive, even if I have to do it on my old PC
- at least get the untouched files on the hard drive. I did not overwrite more than 3gb, so I have near 3tb of data that should be salvagable. How can I get it ? which application is the best ?

I tried partition guru pro 4.3 and it can see some files, if I ask it to recover the files. But I will need another hard drive big enough to get all the data (or reput the data on the old hard drives)

Please, does anybody had that problem and know the solution ?

Also, how can I be sure that it won't happen again, especially on my old PC (silicon image controller). For now, the priority it salvaging the data (over 20 years of photos, videos, cv, games, passwords, etc ...)

I will try to recover the partition if partition guru (at least find it) but I think it won't find anything, because I only had 1 partition and it was at the beginning (and might have been overridden).

Also, is there a usb dock that support hard drive has big as 4tb so I can use it on my laptop to access my 4tb hard drive when I will have fixed my problem ?

 

[stlc8tr]

Don't you still have all of your data on the smaller drives?

Buy a dock that advertises 4TB drive support and you should be good to go.

http://www.amazon.com/s/ref=nb_sb_no...s=4tb+usb+dock

 

[woodspire]

Yeah, clumsy me, I "moved" the data, not copied it. ;(

 

[stlc8tr]

Yeah, clumsy me, I "moved" the data, not copied it. ;(

Make sure you don't touch the old disks. You should still be able to recover the database by running a undelete utility. I've used TestDisk in the past to recover from a formatted partition. It's suppose to be able to recover delete files too.

http://www.cgsecurity.org/wiki/TestDisk

 

[woodspire]

I am running EaseUS Data recovery wizard pro

http://www.easeus.com/datarecoverywizardpro/

Will take 60 hours to parse the hard drive to get the file listing.

In the search display, it is listing some files and folders, so it seems it will be able to recover some of it.

Actually, I could do the same thing on my old hard drives; might be better because the partition table will still be present.

I am guessing the recovery app needs to partition table to know the file type and file name ?

If it's not present (It's my case), then I can only recover the files that the app can recognize based on the file header or an analysis of the whole file structure ?

So an app that can support more file type is better ?

Will let you know what happen in 2 days, when I will start recovering the files. I am hoping I do not have to recover them all to one other drive, since I do not have another 4tb drive, only small ones.

BTW, I ordered the startech usb dock that should support 4tb hard drive.

http://ca.startech.com/HDD/Docking/...Docking-Station-with-Cooling-Fan~SATDOCKU3SEF

Another question, I think my drive was formatted with 512 byte sector. Is it OK or should I use 4k sector for the usb dock to work ?

I read somewhere that's how seagate and western digital format their hard drive in their usb enclosure. Why are they doing that ? So it works under windows XP ?

I only use Windows 7 & 8.

 

[tential]

I don't feel so bad for screwing up now.... Seems like if I had done my plan of formatting my drive when I first got, I still would have run into problems. Seems like I'm not the only person not having fun with 4 TB drives.

 

[fzabkar]

I've seen similar data corruption cases on numerous occasions. The mistake you made was to ignore the fact that the external enclosure has a 32-bit LBA limitation. For a 512-byte-sectored enclosure, this results in an effective capacity limit of 2TiB. This means that as soon as you wrote data beyond the 2TiB mark, it would have wrapped around to sector 0 and trashed your file system.

The number of sectors for the ST4000DM000 model is 7,814,037,168.

If we write this number in hexadecimal we get ...

7 814 037 168 = 0x1D1C0BEB0

http://www.google.com/search?q=7,814,037,168+in+hex

Now if we take only the lower 32 bits, we have 0xD1C0BEB0, ie the 33rd bit is lost.

This equates to a capacity of ...

0xD1C0BEB0 sectors x 512 bytes per sector = 1678 GiB (did you really mean "768GiB" ?)

http://www.google.com/search?q=0xD1C0BEB0+x+512+bytes+in+gigabytes

BTW, Windows is stupid. It determined the drive's capacity from the partition table. It ignored the fact that the enclosure was reporting a much lower capacity. IMO, Windows should have complained of the mismatch and reported that the file system was "raw".

Product Manual Gen 15 ST4000DM000 / ST3000DM003:
http://www.seagate.com/files/static...esktop/Desktop HDD Gen 15/100710254-rev-c.pdf

 

[woodspire]

You are right fzabkar, it was 1.6tb not, 768gb.

It's 746gb and it happen with a 3tb drive, not a 4tb drive. I remembered that value because you will find it more often on google than 1.6tb, because a lot more people asked that question when they got a 3tb drive than when a 4tb drive came out.

 

[Cerb]

I don't feel so bad for screwing up now.... Seems like if I had done my plan of formatting my drive when I first got, I still would have run into problems. Seems like I'm not the only person not having fun with 4 TB drives.

It's any >2TB drive, though the max supported may vary. The USB controller makes are all about cheap, cheap, cheap. It could all have been prevented by always using an ATA converter, instead of custom MSC implementations, or trying to support the ATA-6 (ATA100, ca. 2002) spec, but no, they can't be bothered to do things like that (my old USB 2.0 JMicron-based dongle handles big drives just fine...but, it presents an ATA controller that modern Windows and *n*x have drivers included for, not an MSC).

Aside: ~746GB = 3TB - 2TiB
((3*(1000^4))-(2*(1024^4)))/(1024^3) <- it wants to turn into LISP
It's an artifact of the 32-bit registers rolling over when accessing above 2TiB.

 

[woodspire]

I was not able to recover anything from the 4tb drive because stupid windows had created a new partition over the valid one when I re-drag some files after reaching the 2tb limit.

What I did was recover the files from all my other drives. I recovered 85% of what was on the drive, so I feel lucky.

I bought a startech usb 3.0 dock with fan that support 4tb. It works perfectly now.

 

[tential]

That's a bummer . I dropped my first 4TB drive while it was in use. Went to move my Laptop with it still connected, and BOOM, fell over. Not cool.

 

[twoj]

I thought I would share my present experience

Some time ago I had bought a Rosewill (newegg brand) USB3 external USB hard drive enclosure, I just pulled it apart to find that its running with the
JMicron JMS539 (incidentally the same as in the [FONT=Arial,Italic]StarTech ID: SAT3510U3VGB).

[FONT=Arial,Italic]I originally had a 2 or 3tb in it without incident, however recently I tried putting a 4tb in it. Like the 3tb I had to partition it on the sata port of my desktop because the USB enclosure would only present the 746gb. So I did the same with the 4tb, I formatted the partition to 1 GPT (recommended for >2TB) and then formatted it within the USB enclosure.[/FONT]

[FONT=Arial,Italic]The drive yesterday appeared as a RAW disk, and every attempt I try just comes back with file system unknown. I believe it is as fzabkar says that it hit 1678GB and the next data overwrote the partition table.[/FONT]

[FONT=Arial,Italic]While the drive is just for backups and I have the original data, so I can wipe the drive and rebackup in a proper 4tb non JMS539 enclosure.[/FONT]
[FONT=Arial,Italic]I would still be interested if anyone knows if its possible to correct the error so I can see the partition again?[/FONT]

[FONT=Arial,Italic]thanks[/FONT]

[/FONT]

 

[fzabkar]

Some time ago I had bought a Rosewill (newegg brand) USB3 external USB hard drive enclosure, I just pulled it apart to find that its running with the
JMicron JMS539 (incidentally the same as in the StarTech ID: SAT3510U3VGB).

FWIW, some time ago someone posted this link:
http://www.station-drivers.com/page/jmicron.htm

Here is an archived version:
http://web.archive.org/web/20130818215410/http://www.station-drivers.com/page/jmicron.htm

Unfortunately the files appear not to have been archived.

 

[twoj]

thanks fzabkar

I didn't try updating the firmware but I assume that this will only prevent the issue happening in the future.

You don't know of a way of undoing the partition table damage that has already occurred so I can see the partition/folder/files now?

It was formatted in NTFS and IIRC NTFS splits a copy of the partition table in 2 different locations of the hard drive specifically so that if there is damage in one that it can restore it from the 2nd copy?

 

[fzabkar]

It was formatted in NTFS and IIRC NTFS splits a copy of the partition table in 2 different locations of the hard drive specifically so that if there is damage in one that it can restore it from the 2nd copy?

There is only one partition table. However there are two boot sectors for each NTFS partition. The first sector of the volume is the primary boot sector, while the last sector is a backup.

You could try a tool such as Partition Find and Mount:
http://findandmount.com/

Otherwise you could use a disc editor such as DMDE to search for Special Sectors.

 

[bigboxes]

Lesson learned: backup. I learned that lesson long ago after quite a few data losses. Backup means more than one location. Just having your data on an external is not a proper backup. My eventual backup will have three sets of data (with the third being offsite). I'm always fearful of the backup not working. It cost a lot of money for me to get that third set of disks. To the OP, sorry for your loss. I'm happy that you got most of your data back.

 

[Nec_V20]

With regard to the data you lost by moving the data instead of copying it, you can retrieve it again with the program "Active@ Partition Recovery". I have used it quite a few times and it has never yet let me down.