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379 posts

Ultimate Geek
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Topic # 201634 27-Aug-2016 16:51
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Hi all,

 

I have 3x HDDs (all SATA):

 

- C: system (120GB SSR)

 

- D: 1000GB for "Recorded TV" and system recovery points (I use Norton Ghost to back-up system after important changes or updates)

 

- E: 500GB for "Videos" and timeshifting

 

 

 

short story, I started having HUGE issues with the HTPC lately (several weeks).Live TV playing perfectly, same for playing "videos". Problem is, all hell broke loose whenever I started to access the physical HDD storing the Recorded TV files. That is, starting to record live TV, attempting to play recorded TV. All OK if I watch live TV or a Video, but starts breaking up, freezing, bad stuttering, etc - when it started to record a scheduled recording. Playing a recorded TV file is actually a nightmare, system freezes up, sometime is working fine for few minutes and then fails, or works fine and freezes if you try to skip...

 

After re-installing Windows, MediaPortal, playing with codecs - all the usual time wasting exercise - it became obvious to me that there is something wrong with the HDD so I ran a diagnostic with HD Tuner, please have a look at the screenshot below:

 

 

 

 

 

 

Obviously there are some errors identified, but my FIRST QUESTION is: how do I make them disappear? Even if that means the affected file is deleted. I would like to avoid formatting the HDD, there are a lot of "recorded tv" files in there... and if it is still there, that means that one day I will find time and watch it.

 

the issue became more evident when I attempted to do a system restore, as Norton Ghost could not do that anymore, error after error, freezing, etc - now, I believe all that is consistent with a HDD physical error.

 

SECOND QUESTION: can the HDD be "fixed" and content preserved (mark bad sectors, loose some files but not all, etc?) or not ( new HDD needed, all content is lost).

 

 

 

Many thanks in advance.





mobo Intel DH55PJ, RAM: 4GB RAM, Nova-T 500 HD + Avermedia Trinity tuner card, Geforce 520 video, 120GB SSD Sandisk + 640 WD + 1000SG, Win7 Home Prem 64-bit, Media Portal 1.15.0; BTC 9019URF Cordless Keyboard, Panasonic 55" (HDMI cable), HTPC Case Silverstone Grandia GD05B.


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2584 posts

Uber Geek
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  Reply # 1618421 27-Aug-2016 18:22
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Sounds like the hard drive is on its way out to me.

 

I suspect it's not so much reformatting as replacing that you need to consider.


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  Reply # 1618427 27-Aug-2016 18:34
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As above.

 

You HDD is dying.

 

Replace your HDD (preferably with a bigger one) before you lose all your data.

 

Do it now.  wink





Sideface


 
 
 
 




379 posts

Ultimate Geek
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  Reply # 1618495 27-Aug-2016 21:16
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Thank you for the replies.

 

I agree, I am looking at replacing the drive. Can I recover some of the files on it? The way I see it, the files not affected by bad sectors should be intact, but the bad sectors (or whatever is happening  there) would prevent proper reading of the HDD.

 

How can I recover the content which is still intact? I will let HD Tune to finish its scan - works very slow - and maybe there will be an option at the end what to do with the bad sectors or affected files?

 

 

 

Can CHKDSK do the same? Mark bad sectors, mark the affected files as "damaged" (or simply delete them, I don't mind) then allow access to the HDD for backup? I would really want to recover whatever files are not corrupt.





mobo Intel DH55PJ, RAM: 4GB RAM, Nova-T 500 HD + Avermedia Trinity tuner card, Geforce 520 video, 120GB SSD Sandisk + 640 WD + 1000SG, Win7 Home Prem 64-bit, Media Portal 1.15.0; BTC 9019URF Cordless Keyboard, Panasonic 55" (HDMI cable), HTPC Case Silverstone Grandia GD05B.


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  Reply # 1618500 27-Aug-2016 21:40
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If the files are important, power down the drive and take it to a pro to recover, the more you do to a drive with mechanical issues the less likly the chances of stuff coming back.

 

If not, then keep doing what you are doing, scanning software can mark the blocks as bad and keep going. The problems come if the issue is caused by something broken off the drive surface when the problems started, that will bounce around inside shreading the surface killing more and more data, or if there is a surface problem then everytime the head flies over it, gets a little more damaged etc. This is basically the equivilant of my car is making funny noises, I will keep driving it and see what happens.





Richard rich.ms

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Ultimate Geek
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  Reply # 1618536 27-Aug-2016 23:29
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A good proportion of the files may be recoverable just by copying them off onto your new drive.  When a drive is dying in that manner, it uses its spare sectors as replacements for the sectors that have gone bad.  So a write to a sector will fail, and the drive will map a spare sector in place of it.  The spare sectors can be a long way away on the drive, so then when you play the file, the drive heads have to move around not just to the next track but all the way across the drive and back again between sector reads.  So reading the file at the point of a reallocated sector can be too slow for video playback, hence the stuttering problems.  But if the reallocation process worked OK, if you copy the file off to a new drive, it may work just fine.

 

The real problem comes with sectors that have gone bad since they were written - when they are read again, they will fail to read correctly and may only read OK after many retries, or may never be readable.  A file containing such a sector can still be copied with the right software, but sectors that are unreadable may wind up with invalid data for the sectors or parts of sectors that were unreadable.

 

Also, you did not detect the fact that the drive was failing until far too late.  Drives have a limited number of spare sectors available for reallocation.  It varies from drive to drive, but around 1500 is a typical number, so you may have used up all the spare sectors on that drive.  After that, writes to bad sectors will not result in reallocation and then a good write.  Instead, the data likely will be written to the bad sector in the hope that some bytes may be written correctly, but there will be a minimum of one corrupt byte in the sector at the time of writing, and probably more when it is read back.

 

So, the thing to do now is to shut down that drive until your new one arrives - make sure you do not do any more writes to the drive.  That includes not deleting any files - that causes writes also.  When the new drive arrives you can then attempt to copy whatever you can from the bad drive to the new one.  It may take a very long time as attempting to read bad sectors will cause multiple retries until the retry limit is reached or a good read occurs.  So a file that would normally take seconds to read can take several hours to recover if it has lots of bad sectors.  I believe the Windows logs will show messages about bad sectors, so you can find out what is happening if you look at them.  So recovering what you can from that drive could easily take recovery software a week or more.

 

I am not sure what Windows software would be best for recovering data from a disk with bad sectors - I have only had to do that on Linux formatted drives in the last few years, and there you can use the excellent dd_rescue software.  I have done some recovery of corrupted CDs and DVDs using Nero RescueAgent, and I think that would work for hard drives also, but I only used that as I already have the Nero package that includes it, so I have no idea how good it is compared to other recovery software.  It did a good job with my problem optical disks.

 

For the future, I highly recommend installing SMART monitoring software on all PCs.  This runs in the background and monitors the status of the SMART data from the drives.  It will pop up or email about any problems such as reallocated sectors the moment the first one happens, if you have it set up to do that.  So once a drive starts going bad, you will know immediately and be able to buy a new one and copy everything off before any data is lost.

 

On Linux systems, the normal SMART software to use is the command line tool SmartMonTools (freeware):

 

https://www.smartmontools.org

 

There is a Windows version of that available, but on Windows systems, I prefer to use the excellent HDSentinel:

 

http://www.hdsentinel.com

 

This is payware, but not too expensive and worth every cent.  It has saved me from bad drives several times now.  If your family has multiple PCs, there is a family licence available to make that much cheaper.  HDSentinel is a full scale GUI program that is much easier to use than SmartMonTools and is kept up-to-date with all the latest drives.  If you happen to buy a brand new drive that it does not yet support, you can use its report generating options to send off the data about the drive to the developer and he will normally add support and make a new (maybe beta) version available in a week or so.


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  Reply # 1618623 28-Aug-2016 10:36
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fe31nz:

 

 

 

There is a Windows version of that available, but on Windows systems, I prefer to use the excellent HDSentinel:

 

http://www.hdsentinel.com

 

This is payware, but not too expensive and worth every cent.  It has saved me from bad drives several times now.  If your family has multiple PCs, there is a family licence available to make that much cheaper.  HDSentinel is a full scale GUI program that is much easier to use than SmartMonTools and is kept up-to-date with all the latest drives.  If you happen to buy a brand new drive that it does not yet support, you can use its report generating options to send off the data about the drive to the developer and he will normally add support and make a new (maybe beta) version available in a week or so.

 

 

+1 for HD Sentinel being absolutely brilliant.





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Master Geek
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  Reply # 1618804 28-Aug-2016 17:18
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Above all mount it READONLY immediately, do NOT allow anything to write to it.




379 posts

Ultimate Geek
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  Reply # 1619153 29-Aug-2016 14:30
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Hi everyone,

 

many thanks for all the replies, HDD will get replaced, it is set to Read Only, and it was removed from HTPC.

 

However, I have a situation which I do not understand: The HD Tuner reports as below (very slow progress - I do not know why?):

 

 

 

 

I agree, it looks very bad.

 

 

 

I also run CHKDSK /F, which to my surprise did not find any bad sectors, here is the log:

 

---------------------------------------------------------------

 

D:\>chkdsk /f
The type of the file system is NTFS.
Cannot lock current drive.

Chkdsk cannot run because the volume is in use by another
process.  Chkdsk may run if this volume is dismounted first.
ALL OPENED HANDLES TO THIS VOLUME WOULD THEN BE INVALID.
Would you like to force a dismount on this volume? (Y/N) y
Volume dismounted.  All opened handles to this volume are now invalid.
Volume label is New Volume.

Stage 1: Examining basic file system structure ...
Deleted corrupt attribute list entry
with type code 128 in file 77.
Deleting corrupt attribute record (0x80, "")
from file record segment 0xFE.
Deleting corrupt attribute record (0x80, "")
from file record segment 0x11D.
Deleting corrupt attribute record (0x80, "")
from file record segment 0x14E.
8640 file records processed.                                                  
File verification completed.
2766 large file records processed.
0 bad file records processed.

Stage 2: Examining file name linkage ...
9014 index entries processed.                                                 
Index verification completed.
  0 unindexed files scanned.
  0 unindexed files recovered to lost and found.

Stage 3: Examining security descriptors ...
Security descriptor verification completed.
Inserting data attribute into file 77.
  189 data files processed.
CHKDSK is verifying Usn Journal...
Usn Journal verification completed.
CHKDSK discovered free space marked as allocated in the
master file table (MFT) bitmap.
Correcting errors in the Volume Bitmap.

Windows has made corrections to the file system.
No further action is required.

 976759807 KB total disk space.
 687273356 KB in 977 files.
       592 KB in 189 indexes.
         0 KB in bad sectors.
    104747 KB in use by the system.
     65536 KB occupied by the log file.
 289381112 KB available on disk.

      4096 bytes in each allocation unit.
 244189951 total allocation units on disk.
  72345278 allocation units available on disk.

D:\>

 

-----------------------------------------------------------------------------


386 posts

Ultimate Geek
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  Reply # 1619209 29-Aug-2016 16:29
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No!!!!  Using chkdsk /f writes to the drive!  Do not do anything that writes to a dying drive!

 

Using chkdsk without any options is OK as it only reads from the drive.

 

The reason chkdsk /f did not find bad sectors is that without the /R option it does not scan all the sectors of a drive.  It only checks the structure of the filesystem on the drive, so it only reads from a very small portion of the drive containing the filesystem data.  If there is a bad sector in the filesystem areas, trying to fix it with chkdsk /f is a really bad idea as you are likely to cause further corruption of the filesystem data and hence lose access to many, many files - potentially all of them.  If you need to fix filesystem data, then the safe way to do that is to use recovery software to do a sector by sector copy of the entire old partition to a new drive.  Once all the data that can be recovered that way has been copied, then you are safe to run chkdsk /f on the new copy of that partition, where you will not cause further corruption by running across unreadable or partially readable sectors, or even worse, have a write of a critical sector fail.

 

The reason HDTuner is running very slowly is due to retries.  Whenever the operating system is unable to read a sector, it will normally go through a retry sequence attempting to get the sector to read.  Typically, it will first simply attempt to re-read the sector in the normal manner using the usual read commands.  But as it has just tried to read that sector, before it can try to read it again, the disk has to complete one entire rotation to bring that sector under the heads again.  That takes quite a long time, and the system will normally do quite a few retries (10 is not uncommon) before giving up on that sort of attempt.  Next, the system will likely do a different sort of retry where it moves the disk heads away from the current track, then moves them back again, before trying to read the sector again.  That is done do allow for possible misalignment of the data for that sector from where the track is placed on the disk.  Moving the heads makes such retries take much longer again than the rotational delay, and again there will be quite a few retries.  If all those retries fail, then the system will normally give up and return an error to the program trying to do the read.  That program (HDTuner in this case), may well then also do retries, and each of those retries will go through the same operating system level retry sequence before giving up.  So a simple read of one sector that normally takes a fraction of a second can wind up taking minutes before it ultimately fails and HDTuner moves on to trying to read the next sector.

 

The rate at which HDTuner is able to scan the disk is an approximation of the rate that recovery software would be able to recover the disk at.  Recovery software is likely to be even slower, if you tell it to use all the possible strategies for attempting recover as much data as possible.


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