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 Post subject: File Errors after copying between HDDs
PostPosted: July 4th, 2011, 6:18 
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Joined: July 4th, 2011, 6:03
Posts: 4
Location: Australia
Hi all,

I've turned here for help because I'm at a loss. I really hope someone can figure out what is going on here, I'll include all details, because I like to think I've been thorough...

SUMMARY

After copying a 1080p vlc file between hard drives, the file no longer plays...

Sound easy? Read on...

Approx 100 1080p mkv files on external HDD Seagate 2Tb USB2 NTFS (henceforth known as HDD A)
copied to WD external 2Tb USB3 (only running at USB2) NTFS known as HDD B

The ORIGINAL files play fine in Vista (bootcamp on macbook pro) (OR under OSX) in VLC
but the copies only play as audio - no video at all...
properties shows the original and copy to be identical...
I didn't trust that, so I used Windiff - it said identical...
SO THEN I copied the BAD COPY to ANOTHER extHDD (same specs as HDD B) and also the desktop
AND IT WORKS - a copy of the bad copy...

Further Testing

Replaced all cables from all drives - NO difference
Replaced HDD B - I took it back, got a new one - SAME THING HAPPENS

Further Information

ALL files (originals and copies) play fine in OSX under vlc
ONLY originals play in Vista
AGAIN, COPIES of copies, on other drives, even identical ones work

Any thoughts on what's going on would be greatly appreciated, I feel like I've taken crazy pills

Duff Man


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 Post subject: Re: File Errors after copying between HDDs
PostPosted: July 4th, 2011, 9:23 
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Joined: July 2nd, 2011, 14:16
Posts: 463
Location: England
I had something simuler happen to me, I had two SETA drives connected to a controller card and when I coped data between the two drives the data, or video was corrupted or failed while playing. I discovered that the data rate was too much for the second hard drive to cope with so it would (Do something) to the file.. either the buffer overloaded and did not copy the video properly or it missed parts. In the end I coped the file to a network server (Slower transfer rates) and then back to the new drive and it seems to work.

Not sure if you have the same problem, but copy one file to a slower transfer source, EG IDE hard drive or Network Drive and see if that works.


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 Post subject: Re: File Errors after copying between HDDs
PostPosted: July 4th, 2011, 10:08 
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Joined: July 4th, 2011, 6:03
Posts: 4
Location: Australia
Hey Shane,

Thanks for your ideas. Unfortunately I don't think it'll help in this case, and I think I've already tried.

USB2 copy to USB3(running at 2) still gives an identical file, but it doesn't play
USB3/2 copy to USB3/2 doesn't work either
USB2 to desktop, (internal SATA) and back to the USB3/2 doesn't work either

all of those destinations, are the one drive that doesn't work, identical to the one I swapped it for and ALSO IDENTICAL to 2 I still have (WD 2Tb USB3), but if I copy to those, or any other HDD (external or internal) it plays fine.

So basically no matter where I copy it from, the 1 destination drive doesn't work (and yes it was swapped, and no other problems with non 1080p files, even files with a larger file size...)

so bizarre...


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 Post subject: Re: File Errors after copying between HDDs
PostPosted: July 4th, 2011, 13:01 
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Joined: May 6th, 2008, 22:53
Posts: 2138
Location: England
@Duff Man,

Althouh you titled the thread: "File Errors after copying between HDDs" I don't see anywhere in your (good) description of the situation, where any program actually reported "file errors". Therefore I think this might be a bit misleading :)

Your only symptom seems to be that one program (something built into Vista? - perhaps Media Player?) will only play the audio of your 1080p VLC files (but without actual error messages), only when they are played from a WD external hard disk. Yet the same file copied from the WD disk onto a Seagate disk, correctly plays video and audio, using that same program.

There are several comments I could make, but in brief, although I politely disagree with some of the suggestions from ShaneWard, he has reminded me that apart from the file contents, the rate of data transfer is also vital for video (due to the amount of data involved - especially for HD). Your tests appear to have confirmed data transfer rate (i.e. throughput) is a strong suspect, since your non-1080p files (from the WD disk) play OK, using the same program where your 1080p files (from the WD disk) do not play OK.

So my starting point, if I was in your situation, would be to investigate/measure the data transfer rates when reading files from your various disks (this is not the same as the raw transfer rates, when just reading from LBA0 upwards). The filesystem on the WD disks, and file fragmentation may be involved. It's also possible that those WD disks are Advanced Format disks. Without going into the details, this technology can certainly affect the write performance - I haven't got one of these disks, to do tests on their read performance. However, if you have any background writes happening on such a disk, while you are playing your videos, especially if the partition is not optimally aligned, then this could affect read throughput.

Depending on whether you always attach the disks to the same USB ports, another possibility is a bottleneck in the data transfer rate for the USB port(s) where the WD disks are attached.

As I said, those comments are just a starting point, but you have several bits of evidence pointing in the direction of data transfer rate (throughput) differences IMHO, and since the WD disks are behaving as expected, that's why the replacement WD disk made no change in your observed behaviour.


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 Post subject: Re: File Errors after copying between HDDs
PostPosted: July 4th, 2011, 20:35 
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Joined: July 4th, 2011, 6:03
Posts: 4
Location: Australia
Hey Vulcan,

Thanks for your thoughts, they seem reasonable, but again I think it's been tried.

A file that will not play on the WD drive, is then copied to an IDENTICAL WD and bam, works.
or that same file is copied to any other drive and it works.
USB slots have been mixed up, cables swapped and, as i said the drive replaced.

If you were to look at my actual desk, upon which my computer sits, you would see a seagate 2Tb, and 3 identical WD 2Tb drives - the file plays fine on any drive, except for one (and the one I replaced)

I understand the data throughput idea (I think) but it's compared against 2 of the same, and they have no problem.

Oh and VLC is the program that can't run the file (while it runs identical copies) but under OSX running VLC everything is fine.

FINALLY the bad drive can play 720p files, that are a larger filesize than some of the 1080p ones (of which none work)


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 Post subject: Re: File Errors after copying between HDDs
PostPosted: July 4th, 2011, 21:23 
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Joined: May 6th, 2008, 22:53
Posts: 2138
Location: England
Duff Man wrote:
Thanks for your thoughts, they seem reasonable, but again I think it's been tried.

What I suggested is a focus for investigation from this point onwards, so you can't have tried that investigation already :) (unless you already have the file throughput benchmark results for comparison?).

Duff Man wrote:
A file that will not play on the WD drive, is then copied to an IDENTICAL WD and bam, works.
or that same file is copied to any other drive and it works.

OK, that wasn't completely clear to me in your post before, but I see it now. That's great, in fact - identical disks, one "works" & one "fails". Focussing just on those 2 disks - identify every difference, and compare everything about them and the way they are being used at the time of "the problem" (ignoring, for the moment, the other disks).

As I noted before, that comparison does NOT just mean focussing on the hardware. The disks will have different drive letters, so from an OS point of view, they are not identical e.g. you can have different settings (like background indexing etc. etc.) set for different drive letters. What other data can you get out of VLC - any logging?

Duff Man wrote:
I understand the data throughput idea (I think) but it's compared against 2 of the same, and they have no problem.

As I said, there are elements of your system which are not identical, even between 2 disks of the same model (e.g. filesystem layout, OS settings etc.). Doing the file benchmarking is something I would be doing to start with.

Duff Man wrote:
Oh and VLC is the program that can't run the file (while it runs identical copies) but under OSX running VLC everything is fine.

Understood - but unless you can find a reason why VLC isn't playing the file under Vista from that disk (i.e. an error message), then you don't know that VLC on OSX isn't just slightly more efficient (for example), or have different error handling, or just able to cope better with whatever the underlying issue is. Lack of a visible problem on OSX does not mean that no problem is occurring - it could just be that OSX (or the VLC compilation for OSX) is handling it differently.

Have you been looking in the Vista System & Application event logs for any clues? Have you investigated whatever VLC does for error logging?

Duff Man wrote:
FINALLY the bad drive can play 720p files, that are a larger filesize than some of the 1080p ones (of which none work)

Yes, I understood that from before - the size of the file has nothing to do with necessary file throughput. The data throughput which is needed, will depend on the file format. So your evidence here about other file formats playing OK, confirms a bottleneck in data throughput somewhere as the likely problem. :)

Since you have already replaced the "suspect" disk (and got the same results) and have another disk that "works OK", then I see no evidence that this is actually a disk hardware problem.

Since I'm remote from the problem, I doubt I'll be able to find your "smoking gun" - in my experience, it is much more efficient to have someone in front of the equipment who is familiar with this kind of troubleshooting. Good luck with whatever you decide to do :)


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 Post subject: Re: File Errors after copying between HDDs
PostPosted: July 5th, 2011, 3:02 
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Joined: July 4th, 2011, 6:03
Posts: 4
Location: Australia
well here are the last few pieces of info I have gathered.

Basically I gave up, I had a spare WD 2Tb USB2 lying around, so I copied one file to that, it worked, great, whatever, that'll do. So I copied over a Tb more. Now none of them work, This is the 3rd different drive, they were all brand new, only the video files, so I thought hmmm, maybe vista is using drive H: in some way or perhaps there is some voodoo curse on that letter? Well, I'll change it, didn't help.

I checked all the settings I could find for indexing, or backing up or anything that might make this drive not work, but honestly, it's no longer THIS drive, it's 3 perfectly good drives with 180 mkv files on it, and there is still 800gig free. I'd be willing to bet that ANY HDD IN EXISTENCE would not be able to function with this line up of files, it's Pandora's box of movies, combine them and you ARE SCREWED!

So, I think it's time to update to Windows 7, which I don't have time for, but I don't have time for this crap either.

Thanks for your help guys.

Duff Man

PS Vulcan if you read this, what program would you suggest to test the data rates you were talking about? thanks


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 Post subject: Re: File Errors after copying between HDDs
PostPosted: July 6th, 2011, 5:30 
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Joined: July 2nd, 2011, 14:16
Posts: 463
Location: England
Have you tried playing the files using windows media player?


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 Post subject: Re: File Errors after copying between HDDs
PostPosted: July 6th, 2011, 10:10 
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Joined: February 13th, 2010, 9:44
Posts: 208
Location: san diego, ca.
Try a different computer- perhaps thae answer is the computer


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