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Dead Drive: How to bypass bad sectors?

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July 8, 2012 7:09:24 PM

I have a fairly new WD external HDD that bit the dust while I was writing a few video files to it the other day. The writing was on the wall as the drive would randomly disconnect from the computer for no reason and needed to be power cycled to return.

Chkdsk wouldn't work on the drive. I'm using EaseUS Partition Master to test the drive now, it's only 25% done yet it has already detected 44270 bad sectors. Is there any way to isolate and avoid these bad sectors just to access the drive once more and salvage whatever is on it? I'd like to do this before I RMA.

The drive was used mainly as a backup, but there are some unique files I need to pull off. I used Photorec to recover some of the files, but the problem is nothing is named and it will take weeks to sort through to figure out what is a backup and what is an original. It took about 5 hours to complete that, and that wasn't even the entire drive. It's a 3TB so if I recovered the entire drive, the estimated time of completion was 150 hours and increasing.

TL;DR I don't care about the corrupt files on the bad sectors, what's gone is gone. I just want to be able to access the drive and selectively copy off the small percentage of files I need. Any help would be greatly appreciated!
a b G Storage
July 8, 2012 8:03:08 PM

Call WD and RMA the drives so you can get replacement ones.
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July 8, 2012 8:16:15 PM

I plan on doing an RMA but I would like to recover some of the files first, hence the topic..
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July 8, 2012 9:36:08 PM

That is very high amount of bad sectors, you will have to use data recovery services.
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July 9, 2012 12:19:45 AM

The drive will automatically assign new sectors and the count is reported in SMART data. The sectors failing shoudl be clusters, and file systems try to cluster file data to improve read times. There is a chance you can get data.

Download WD's tool from their support page. Have it do a surface scan (or whatever they call it in the tool). Then look at the smart data to see how many sectors you lost.

These are typically 512 byte sectors (although maybe advanced format drive with 4K sectors). 512 bytes times 44K failed sectors (so far) = 22MB of bad data. 22MB of failed is huge, but not as a percent of the drive.
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a b G Storage
July 9, 2012 3:19:46 AM

TestDisk, Data Recovery
TestDisk is powerful free data recovery software! It was primarily designed to help recover lost partitions and/or make non-booting disks bootable again when these symptoms are caused by faulty software, certain types of viruses or human error (such as accidentally deleting a Partition Table). Partition table recovery using TestDisk is really easy.

TestDisk Step By Step to recover lost partitions and repair damaged FAT/NTFS boot sector
Recover deleted files from NTFS partition

NOTE If seeked lost file are still missing, give PhotoRec a try. PhotoRec is a signature based file recovery utility and may be able to recover your data where other methods failed.

PhotoRec is file data recovery software designed to recover lost files including video, documents and archives from hard disks, CD-ROMs, and lost pictures (thus the Photo Recovery name) from digital camera memory. PhotoRec ignores the file system and goes after the underlying data, so it will still work even if your media's file system has been severely damaged or reformatted.
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a b G Storage
July 9, 2012 4:47:56 AM

Don't get to high hopes, usually the data is unrecoverable...... (Except professional data recovery company)

Every time u do copy/write the data or doing disk check/test it will hasten/add the damage to the disk........ (If the hdd is already broken)
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September 10, 2012 9:08:47 AM

Try the tool PBD(Partition Bad Disk) which can bypass bad sectors and create healthy partitions.

dedbeats said:
I have a fairly new WD external HDD that bit the dust while I was writing a few video files to it the other day. The writing was on the wall as the drive would randomly disconnect from the computer for no reason and needed to be power cycled to return.

Chkdsk wouldn't work on the drive. I'm using EaseUS Partition Master to test the drive now, it's only 25% done yet it has already detected 44270 bad sectors. Is there any way to isolate and avoid these bad sectors just to access the drive once more and salvage whatever is on it? I'd like to do this before I RMA.

The drive was used mainly as a backup, but there are some unique files I need to pull off. I used Photorec to recover some of the files, but the problem is nothing is named and it will take weeks to sort through to figure out what is a backup and what is an original. It took about 5 hours to complete that, and that wasn't even the entire drive. It's a 3TB so if I recovered the entire drive, the estimated time of completion was 150 hours and increasing.

TL;DR I don't care about the corrupt files on the bad sectors, what's gone is gone. I just want to be able to access the drive and selectively copy off the small percentage of files I need. Any help would be greatly appreciated!

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a c 316 G Storage
September 10, 2012 7:24:33 PM

Clone your drive sector-by-sector using a tool that knows how to work around bad sectors, and then use data recovery software on the clone.

A good freeware cloning tool is ddrescue:

http://www.gnu.org/software/ddrescue/ddrescue.html

Ddrescue can perform multipass cloning. It clones the easy sectors on the first pass, and attempts the more difficult ones on subsequent passes. It can also clone your drive in reverse, thereby disabling lookahead caching. It keeps a log, allowing it to resume after an interruption.

The following thread discusses various freeware and commercial cloning tools:
http://forum.hddguru.com/the-best-disk-cloning-hardware...
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a b G Storage
September 11, 2012 2:25:15 AM

As fzabkar suggests ddrescue is a very good free option for cloning drives with bad sectors.

Another is R-Studio it's non-free but some find it easier to use... http://www.***
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Anonymous
a b G Storage
February 25, 2013 9:54:43 AM

Seems that everyone is more interested in data recovery than prevention of further data writing on this bad sectors… Anybody knows any program that MARKS bad sectors and prevents system from putting file on this location?
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March 3, 2013 4:49:03 PM

Quote:
Seems that everyone is more interested in data recovery than prevention of further data writing on this bad sectors… Anybody knows any program that MARKS bad sectors and prevents system from putting file on this location?




I'm gonna point out two very SMART programs for you and others interested that such things along with a grip of other wonderfully useful/helpful things..

1st one --- HD Tune Pro 5.00 (less then 10mb in total size & easy to use from a USB flash or other source)
HDTune.com retails $35us or $00.00 from PB or a friend emailing it

2nd one --- StableBit Scanner the gold standard in this sort field.. And other then mailing a HHD off to company to fix/recover for like $200 this program has the best chance of recovering files,and the bad sectors they are in.. And everything else you could think of (It just doesn't give reach arounds or windows sills)
StableBit.com/Scanner Has a 30day free trial, and costs a totally worth it price of $24.95
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October 19, 2013 5:01:26 PM

**********SOLUTION......I JUST HAD THE SAME PROBLEM AND WAS ABLE TO SOLVE IT TODAY*************

To the original poster (dedbeats) and anyone else looking to solve this problem: I just successfully used CloneZilla to solve this very same problem, today. My drive failed a few weeks ago and it took me this long to figure out how to copy the data off of the failing drive, which has tens of thousands of bad sectors too. I used CloneZilla. It is a FREE open-source program. It is available here, as a standalone program. I followed the instructions to put it onto a USB thumb drive and boot off of it: http://clonezilla.org/downloads.php.

You can also get it here, included in Parted Magic, for a small fee of $5. Parted Magic has many other utilities too, so this is very useful: https://partedmagic.com/downloads.

Important: while using CloneZilla, in order for it to recover AROUND bad sectors, but not fail due to bad sectors, make sure to run it in "Expert" mode when the option comes up, and select the "-rescue" option. See here for screenshots of what I am talking about: http://clonezilla.org/clonezilla-live/doc/03_Disk_to_di....

Final notes: this worked perfectly for me. I did an entire hard drive clone, from my bad drive to a good drive of equal or greater size (equal in my case). Also, normally, doing this operation requires about 4 hrs. for the amount of data I have, however, the "-rescue" option took more like 12 hrs. since it had to work around bad sectors. Now, I have an external hard drive with a duplicate of my system when the drive failed, so that I can access my old files from my new operating system and recover data as needed, so long as it didn't fall on a bad sector and get corrupted.

Also, I highly recommend using FreeFileSync (also open-source) as a data backup program. http://freefilesync.sourceforge.net/. I discovered it within the last 2 weeks. I reinstalled my new operating system a couple weeks ago, and copied my backed-up data back onto it. Then, I searched for a better way to do backups, withOUT having to use backup software which is unreadable (via Windows Explorer) on the backup end. I discovered FreeFileSync after many hours of searching. I am using it to backup ~65GB of data on my new hard drive, and it does a perfect file-for-file duplicate from source to destination. Now that I've done the first copy, it only takes ~3 min. to update the destination copy each time I click the shortcut to run a script (batch file) on my desktop. Super handy; super nice. Now, I can avoid major data loss in the future.
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October 20, 2013 6:29:00 PM

I was mistaken, my drive does NOT have tens of thousands of bad sectors, but rather, it has tens of thousands of "Raw Read Error Rates," and only 82 bad sectors, according to the SMART data. However, while I was watching CloneZilla operate, it threw an error for each bad sector it could not read (though it continued past them eventually since I used the "-rescue" option), and it appeared to me that it had more like hundreds of bad sectors, not 82. I can't confirm that number, however.

What I can say is that the drive is damaged enough that when I used Parted Magic to try and write zeros to the drive, in order to securely erase it, it failed, and actually froze the Parted Magic operating system. Also, I used SeaGate's "SeaTools for Windows" hard drive repair/analyzer program, and it also failed to securely erase the drive, yet it did work on a healthy hard drive of the exact same make and model. Note: SeaGate is who is doing the warranty for my hard drive. Even though it is a Samsung drive, SeaGate handles the warranties for it.

Kyle, I installed HDDExpert, but it seems to only be able to read the SMART data in the internal hdd of my laptop. My bad hdd is now in an external hard drive enclosure, so I used GSmartControl version 0.8.7 instead, which is a GUI version of Smartmontools. It can be downloaded free here: http://gsmartcontrol.berlios.de/home/index.php/en/Downl.... I am confident that it read the exact same thing as HDDExpert would have read, however, because I compared its results on my new internal hard drive to the results from HDDExpert, and they were identical.

As for my bad hard drive (now in an external enclosure), which I successfully cloned via CloneZilla, here are the SMART data results from GSmartControl:

-I have no idea how to insert an image here, so I am uploading it to Google Drive then posting a link.
Image 1: https://docs.google.com/file/d/0BwHItOaHOOvdenlKWDJ4aDY...
Image 2: https://docs.google.com/file/d/0BwHItOaHOOvdY2lZTzdWUmh...

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October 21, 2013 2:29:23 PM

Kyle_Katarn said:
fzabkar said:
Try Bad Block Copy for Windows:
http://alter.org.ua/soft/win/bb_recover/

It's like ddrescue, but it allows you to target specific files.

As for Seagate's Raw Read Error Rate SMART attribute, the raw value is a sector count, not an error count.

See the following article:

Seagate's Seek Error Rate, Raw Read Error Rate, and Hardware ECC Recovered SMART attributes:
http://www.users.on.net/~fzabkar/HDD/Seagate_SER_RRER_H...


That's the right interpretation of these figures


Interesting, then I guess I was right the first time! It does have tens of thousands of bad sectors. Anyway, the drive was mailed back to SeaGate today. Glad to have this behind me. Computers are a hassle.
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a c 316 G Storage
October 21, 2013 2:52:33 PM

The drive reads 250 million sectors and records the number of errors. The raw value shows the number of sectors that have been read, not the number of errors.
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October 21, 2013 4:47:20 PM

fzabkar said:
The drive reads 250 million sectors and records the number of errors. The raw value shows the number of sectors that have been read, not the number of errors.


Ok you lost me. The raw value (Raw Read Error Rate) is 35876. If the drive reads 250 million sectors, 35876 cannot be the number of sectors that have been read, since 250,000,000 does not equal 35876. I must not be understanding you correctly.
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a c 316 G Storage
October 21, 2013 5:28:35 PM

The RRER attribute is a rolling average. The drive counts the number of errors in the last block of 250 million sectors and then computes a logarithmic normalised value over this block. A normalised value of 120 reflects 0 errors, ie a perfect score.

The raw value of the attribute starts off at 0 and increases to 250 million. When it reaches 250 million, this number rolls over to 0. The drive then begins monitoring the error rate over the next block of 250 million sectors.

In your case the drive has read 35876 sectors in the current block. That's all that this number means. It says nothing about how many errors were recorded in this block.
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October 22, 2013 6:54:34 AM

I see. So the indicator that my drive is bad is the fact that the RRER "norm-ed value" is 1, NOT the fact that the "Raw Value" is 35876?

Also, I'd like to add that on my "certified repaired" hard drive, of the exact same make and model, the RRER "norm-ed value" is 100, and the "Raw value" is 202. What do you make of that? Does your understanding of the SMART values allow for differences in the "Raw value" among different drives of the same make and model?

Lastly, it just occured to me that I need to add that although SeaGate is the warranty provider for these 2 hard drives, Samsung is the maker. Not only that, but I suspect that my drives do NOT follow SeaGate's SMART algorithms, as when I checked the information on them, per SeaGate's instructions, using SeaTools for Windows, the Seagate utility says that SMART is not even supported on my Samsung drives, yet you can see from my images posted above that clearly SMART is supported on these drives. That indicates to me that SeaTools can't even read, detect, or use the SMART data on my Samsung drives, despite the fact they are covered under warranty by Seagate. If that is the case, these drives must not be using Seagate's SMART algorithms at all.
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a c 316 G Storage
October 22, 2013 12:54:10 PM

You actually have a Samsung drive that has been rebranded as a Seagate. Therefore my interpretation of the SMART data does not apply. Samsung calculates the SMART attributes in a completely different way. That said, a normalised RRER value of 1 denotes a failure in that attribute for both Samsung and Seagate drives. The raw value of the RRER for a Samsung drive probably reflects actual read errors, but I'm not certain. You should probably compare your SMART data against others via a Google search.

As for SeaTools, it is often the case that SeaTools for Windows (and other HDD tools) have difficulty communicating with certain SATA controller drivers. In this case you will most probably find that SeaTools for DOS will see the drive and correctly detect the SMART data.


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October 22, 2013 5:25:47 PM

Thanks for the information.
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October 28, 2013 3:20:08 PM

If you jump back to my comment on 19 Oct. you'll see where I came in. I was simply posting a helpful tip to those who have a drive with bad sectors but want to recover data. I successfully recovered my data off of a failing drive with bad sectors (refer back to that post) that would no longer boot properly or run Windows without freezing. I used CloneZilla with the "-rescue" Advanced parameter set.
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