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External drive going bad? / salvageable?

Discussion in 'DIRECTV HD DVR/Receiver Discussion' started by cigar95, Jun 9, 2011.

  1. cigar95

    cigar95 Legend

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    May 23, 2008
    OK, when I get a chance (things are a bit busy at the moment) I will write up the whole procedure.

    Also, remember that I ran MHDD way back at the very beginning, and the physical drive itself was fine. (You commented at the time on a possible issue with the SATA connection, but since that was the connection to the computer and not the connection to my DVR, it was likely a non-issue.)
     
  2. P Smith

    P Smith Mr. FixAnything

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    I don't remember - was it SMART-Scan-SMART three step process ? ...
     
  3. P Smith

    P Smith Mr. FixAnything

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    While we can bounce around SMART-noSMART, value-novalue posts, I did a lot of work for IT, enough to appreciate a value of SMART, the programs and did salvage of many gigabyte of data for companies and did save money for its recovery. Perhaps the forum is not right place to discuss the aspects ... Or you are not experienced in IT chores.
     
  4. cigar95

    cigar95 Legend

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    May 23, 2008
    I think I just did Scan-SMART.

    The scan reported no changes at the time.
     
  5. bobcamp1

    bobcamp1 Icon

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    Did you do the scan with remap on? That's the most useful feature of that program. Do that, then *immediately* copy the data off the drive. xfsdump/xfsrestore should work after that. If that doesn't work, then what you did appears to be an excellent plan B. I think in either event, you may have a few recorded programs that won't play back properly, but it's better than losing everything.

    You can peek at the SMART parameters after the scan. If they show everything's OK, you still could very well have a failing hard drive. If they show things are failing, then your hard drive is definitely dying. According to Google, 56% of failing hard drives do NOT show any problems when you look at their SMART data. According to my "experience" (which is more than most people), that number is indeed around 60%.

    I used to use Spinrite instead of MHDD, but it has too many incompatibility problems with modern motherboards for me to recommend it anymore. And it's not free.
     
  6. cigar95

    cigar95 Legend

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    May 23, 2008
    I believe I ran the scan with remap on, although at this late date several weeks later, I can't be sure.

    In any case, I believe that my problem was with the *content* of some key file being corrupted, rather than with bad sectors or anything like that - a standard xfsdump/xfsrestore copied the entire disk without any warnings or error messages, and the result was a disk that showed exactly the same "frozen" behavior as with my original drive. (That observation doesn't constitute "proof", but it might qualify as circumstantial evidence.)

    So far I have found one of my recordings for which every one of the recording segments is no longer on the disk. (Each recording is stored in a very long series of 16 Mb files - depending on the show, it takes about 150-200 of these per recorded hour.) The transfer process was a little flaky when I was doing it via a USB interface, but it seems more reliable (and faster) doing it here at the office with eSATA.

    I also have to say, the whole process of exploring the file structure and figuring out which files needed to be transferred and which permissions needed setting has been an interesting one.

    I could not have done it without the help of the dbstalk board members - for instance, I might never have figured out that I needed to copy the recording segments using the "xfs_rtcp" command, rather than a typical unix "cp". I copied a few programs using the latter, since it was much faster, and the DVR was perfectly happy playing them back. The only problem was that cp sent them to the regular partition, which is only 16 Gb, rather than the real-time partition, which is over 900 Gb. So it filled up very quickly.

    Although I knew it was likely doomed to failure, I contacted DTV customer support and asked if they could put me in touch with someone in engineering to ask a few more questions about the file structure on the disk. When I described what I was trying to do, the reply I got was pretty much "you're not seriously trying to do that? We have no way to help you."

    So as I said before, I hope to soon have a chance to write up the process in great step-by-step detail and post it back. I expect there are probably very few who want to do this themselves, but there will probably be some, and it would make me feel good to make a small contribution to the body of knowledge here.
     
  7. P Smith

    P Smith Mr. FixAnything

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    Go ahead.

    [I would do that if just one person would express his willing to repeat same procedure. Perhaps, an author of the program would see more interest to it and will make it work faster.]
     
  8. cigar95

    cigar95 Legend

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    May 23, 2008
  9. cigar95

    cigar95 Legend

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    May 23, 2008
    I need to follow up on this old thread because I discovered there was a trivial fix to my problem. After all the work I did learning to copy the programs to a new drive, the fix is no longer necessary, but had I merely wanted to get the bad disk working, this very quick fix would have done the trick.

    Recall that my recordings on the bad drive were undisturbed, but that there was something in the "system files" that caused the boot process to hang. So the solution was to simply replace the operating system.

    With a brand new hard drive, I booted the DVR, which installed a fresh operating system on it. Made sure to allow time for it to download the latest system updates.

    Then I used the well-known process, using xfsdump/xfsrestore, for copying an entire drive - but I copied *from* the virgin drive *to* the corrupted drive, remembering that this process will overwrite existing files, but will not touch any other files.

    Because this drive had no recordings on it, the copy process took all of 23 seconds. In the process, the fresh system over-wrote whatever file had caused the system to go bad - ergo, the old drive now boots just fine, and all of the old recordings are still there, except for one. Presumably that one was somehow involved in the corruption.

    Since all my content had already been transferred to a newer, safer, and larger drive, this latest process was really just for my own intellectual curiosity. I can keep the drive around in case I need it in the future, or maybe I'll just reformat it and use it as a regular computer drive.
     
  10. P Smith

    P Smith Mr. FixAnything

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    Lucky, the xfs programs doing not exactly dump -> restore, but dump -> replace_same_files_folders_only.
     
  11. cigar95

    cigar95 Legend

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    May 23, 2008
    Some of the postings in those long threads on the disk copying process made it clear that it would overwrite, but not otherwise erase. So it doesn't surprise me that this worked.

    What bugs me is that I didn't think of this back when I was first trying to solve the problem. It would have saved me a heck of a lot of time, although I might never have discovered the fun little trick for transferring individual recordings.

    (I *did* try the same copy in the opposite direction, but that one failed because it just copied the corrupted file onto the new disk.)
     
  12. P Smith

    P Smith Mr. FixAnything

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    Anyway, we should say thank you for developing new ways of the common task of rescue recordings from failed DVR drives.
     
  13. purrdue

    purrdue New Member

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    Hi. I'm having a similar problem with my drive. I don't know if it's my HD dvr-hr 20 or my new wd 2 TB eurs I just got. I've been using the new drive for about a week and everything was working fine on a daily basis I would switch between my old Hitachi drive and the eurs drive at night to record new shows. I had about 10% filled and 2 days ago when I switched the drives it got stuck on the step 1 on the checking satellite settings for over 20 minutes so I reset same result, did that 3 times waited a total of an hour and it wouldn't boot went back to old drive booted no problem. After a couple of hours tried new drive again and it booted up this time but it did a software update and erased all programs. I tested it again after recording something and it restarted fine and even worked the next day when I switched. But same thing happened today wouldn't boot and then when it did software update and programs gone. Any suggestions what could be going wrong? I'm pretty sure I'm going to send the drive back but do I stick with the same kind. I can't have my programs keep disappearing on me and I like to keep seasons at a time before I start watching them. Thanks for any suggestions to my very annoying problem. Sorry for such a long post. SS
     
  14. Rich

    Rich DBSTalk Club DBSTalk Club

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    First thing I'd stop doing is switching drives constantly. That's a great way to screw something up. You sound like someone who should have multiple HRs. That solves the problem of having to switch drives constantly.

    I know someone is gonna jump on what I say next and say that they've got an EURS that is running perfectly, but I've read far too many posts where the poster says that they've had that same sort of problem with the EURS. I actually kinda like the EARS, especially with a 20-700.

    You'd probably be all right with another EURS if you stop switching back and forth between externals. In layman's terms, you're confusing the 20. If that's a 20-100, it's confused enough. If it's a 20-700, you might be on the verge of wrecking one of the best DVRs D* has produced.

    Rich
     
  15. purrdue

    purrdue New Member

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    Sep 5, 2011
    Thanks for your response. I do have more than 1 dvr I have 4 and the reason I have been switching the drives back and forth is I want to change the drive to the new one permanently but I have 75% of stuff I still have to watch on my old drive. It's a HR-20/700 by the way. I certainly wouldn't trust using the new drive for a while filling up 25% or more and then swap the drives after a couple of months to watch something on my old drive and when I went back to the new drive all my programs would be gone.
     
  16. P Smith

    P Smith Mr. FixAnything

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    Rich, you're over emphasize the swap process. :)

    It's just same as the DVR turning OFF and ON.
    Nothing unusual.
    But the HDD model ... that's the whole idea of checking its reliability.
     
  17. cigar95

    cigar95 Legend

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    May 23, 2008
    purrdue, I can tell you right off the bat that your problem is different than the one I had. I had somehow had one or more files in the operating system get corrupted, and once I installed a new OS on the same drive, right on top of the old drive, it worked fine, and with the old recordings still intact.

    The fact that you're seeing the problem repeated with what is purportedly a fresh OS each time seems to say that it's likely a problem with the drive itself.

    I know that my thread buddy PSmith is going to recommend looking at the SMART data, and that's a good idea, but I would try one other thing as well - load the drive onto a computer and reformat it - doesn't matter what you reformat it with, just do something that will wipe out all the old stuff. That way, if the DVR re-installs are leaving some of the old system intact, the next reinstall after you reformat should truly give you a fresh system.

    (Having said this, it may be that the DVR really does do a full reformat when it installs a fresh OS - if that's the case, I'm sure someone will step in and say so, and in that case, my suggestion is just redundant.)
     
  18. P Smith

    P Smith Mr. FixAnything

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    cigar95, just small remark (I thought it was once, but ..) - the DVR's Linux OS do not install OS or its parts onto the drive. The Linux creating file system and then use it as a storage of temporary data, yes - user's recordings/schedules/etc are temporary data and system logs, pure system temp files. But not OS parts - all the companies are too paranoid to allow ppl examine/modify programs and the OS data. Perhaps TiVo gave them the scare experience when everything what USERS wants was done ;).
     
  19. cigar95

    cigar95 Legend

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    May 23, 2008
    Yeah, I was a bit cavalier about using the term "operating system". Replace all that with "DTV working system files" - the stuff that the DVR needs to boot and show you your GUI and such, but apart from the data related to your specific recordings, scheduled programs, favorites, and so on. But not the Unix system itself.
     
  20. Rich

    Rich DBSTalk Club DBSTalk Club

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    That was the first thing I thought of when I read his first post. I think I'll stand firm on that opinion. I don't switch my external HDDs around and I have no problems such as he has. As for the EURS, I doubt that the folks that have them working are swapping them back and forth either. Something caused that 20-700 to wipe out all his recordings, something that's never happened to me.

    And what's the big difference between what he's doing with his externals and what most of us do with ours? Going back and forth with them.

    Rich
     

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