Current Pending Sectors: How bad is it? How to stop it getting worse?

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  1. Posts : 40
    Windows 10 Home 64Bit OEM, Version 1909 (OS Build 18363.1139)

    Current Pending Sectors: How bad is it? How to stop it getting worse?


    Two of my external hard drives have both developed "Current Pending Sectors".

    1TB-drive: 11 Currently Pending Sectors initially. Evacuation/Backup went mostly fine, but rose to 12 Current Pending Sectors while copying a folder containing the most recent data. Further rose to 15 when checking Rightclick->Properties of said folder to calculate total file size / file count.

    8TB-drive: 8 Current Pending Sectors, 8 Unrecoverable Sectors. Drive had no Pending Sectors just a week prior. Also, this drive is where I had been backing up the 1TB drive to, and I suspect the folder "causing" those Pending Sectors may be the backup of the folder causing them on the 1TB drive. Coincidence?

    Obviously I'll have to evacuate my data at least temporarily (for which I'll need to buy a new hard drive first), but I have questions about that.



    The backup for one of the folders on the 1TB drive had failed. A check with Crystal Disk Info revealed 11 Current Pending Sectors initially, though this eventually increased while evacuating my data / updating my backup;

    Problems only arose on the folder with the most recent data, about ~200 GB that hadn't previously been in my backup at all, so rather than use the backup tool, I just drag'n'dropped the folder to my 8TB drive.

    Regular drag'n'drop copying worked fine - or at least I think it did, there was no obvious error message waiting for me when I checked if it was done copying, and the total file size / number of files count seems to match. *shrug*

    After copying that folder and all its subfolders (~200 GB), Current Pending Sectors count had gone up to 12.

    And just from checking the total combined file size / number of files for the folder via Rightclick>Properties to compare against the backup, within 40 minutes, the Current Pending Sector count shot up to 15.

    I've vaguely read about the distinction between "Current Pending Sectors on Write" and "Current Pending Sectors on Read". I'm guessing this is the latter. Probably some damaged files in there?

    Current Pending Sectors: How bad is it? How to stop it getting worse?-current-pending-sectors-1tb-drive.jpg

    I'm not fully satisfied with my backup yet, especially since I still want to run my backup tool (Synchredible) in "compare file contents" mode to verify the backup's consistency, but after seeing the Pending Sector Count go up I've shut the drive down until such a time I know better how to handle that without causing more damage.


    ...And then, about a week later, the 8TB drive to which I had just backed up the 1TB drive also developed Current Pending Sectors... literally 4 days after the 2 year warranty ran out. -_-

    Crystal Disk Info didn't show any issues with the 8TB drive just one week prior. Now there were suddenly "8 Current Pending Sectors", "8 Uncorrectable Sectors". I then shut the drive down and haven't used it since.

    Current Pending Sectors: How bad is it? How to stop it getting worse?-current-pending-sectors-8tb-drive-before-after-.jpg

    The only noteworthy things I did on that drive in that week were:

    a) Running a program which created 5000+ empty directories in a fairly short time as the by-product of a test. (I don't know if something like that can cause problems?)

    b) While I'm not fully happy with my 1TB's backup yet, I'd decided to treat at least part of what had originally been a Backup as the new Master instead, reversing the Backup/Master role, and added new files to it, which included adding files to the directory that corresponds to the troublesome folder on the 1TB drive. Which seems like too much of a coincidence to me.

    Dumb question: Drag'n'drop-copying a folder afflicted with "current pending sectors" from one drive to another can't somehow "infect" the other drive, right? o_O?

    I don't know if it is important, but for the sake of completion it may also be worth mentioning that, a few weeks prior to all this, I had moved a very large amount of files off of the 8TB drive (~2.1 TB) to make space for updating my backups - though this worked without any issues, and there were no pending sectors detected afterwards (yet).

    I also make use of hardlinking duplicate files to conserve space without breaking my file organization, just fyi in case that's somehow important.


    My current plan is to buy a new hard drive and evacuate all my data there.

    However, exactly what hard drive size I'll need, and if I have to buy a second hard drive as a new dedicated backup drive depends on the answers to my following questions.


    Relevant Questions:

    1) Asides from the one time my backup software failed to parse a folder and crashed, I didn't notice any obvious problems with either of the drives.

    If it wasn't for Crystal Disk Info telling me about the Pending Sector issue, I wouldn't even know anything was actually wrong.

    So, how bad it is?

    2) How do I stop it from getting worse while evacuating my data elsewhere?

    I haven't run chkdsk yet, because I've heard that chkdsk will likely delete files. And since I no longer have a guarantied backup, I'd like to first make a new one - which will involve backing up the entire drive from scratch and re-copying every single file again (including a more thorough second pass in "compare file content" mode to verify the backup), which will also touch the same folder I suspect the Pending Sectors to be in again and thus may aggravate the issue; something I'd like to prevent from worsening the situation.

    3) How likely is chkdsk to delete files during its repair attempt?

    Is there a way of running chkdsk (or similar) non-destructively to find that out in advance what would get deleted?

    4) How can I find out which files exactly are damaged so I can make an informed judgement if anything important has been lost?

    If I know what's damaged, maybe I can restore it from backup? Maybe I can re-download it from somewhere?

    Obviously I'm guessing it's in that one troublesome folder with the most recent files (and its counterpart on the backup drive), but I can't be sure that's the only folder affected, and even if it is, that's still a few hundred subfolders with 200 GB of files.

    A full list of full file paths would be most useful here.

    5) Even if I fix the Pending Sector issue, how reliable are these drives going to be in the future?

    Can I go right back to using them "normally"?

    If not, can I still use them as backup- (weekly, monthly?), or long-term storage devices?

    The answer to this question also will decide what new hard drive(s) I'll have to buy.
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  2. Posts : 21,421
    19044.1586 - 21H2 Pro x64

    HedgeToaster, hello and welcome to TF ,

    Get a second opinion using HD Sentinel app.
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  3. Posts : 21,421
    19044.1586 - 21H2 Pro x64

    I have started running CDI full time in my system tray recently to prevent a surprise like yours happening to me after reading about other peoples drive failures here and there . I have also configured HD Sentinel to run at startup every time, so I can see what it says too, then exit it.
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  4. Posts : 21,421
    19044.1586 - 21H2 Pro x64

    Sorry, I can't really answer your tough questions

    Others will come along with suggestions ........ maybe @jumanji ji has some suggestions.
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  5. Posts : 11,629
    Windows11 Home 64bit v:23H2 b:22631.3374

    Hi @HedgeToaster

    Just google "Current Pending Sector counts" and you get all info on it.

    The short answer is if the Current Pending Sectors count keeps increasing, it would mean that those are not getting remapped and drive failure is imminent sooner or later ( which no one can predict) alongwith complete data loss.

    The backups you do on such a drive are no longer relliable.

    Bad sectors cannot be repaired. Stop using those HDDs and do fresh backups on the new HDD. There is no two ways about it. ( A true backup means that you have all the data on two different drives so that in case one fails you still have it on another drive.)
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  6. Posts : 40
    Windows 10 Home 64Bit OEM, Version 1909 (OS Build 18363.1139)
    Thread Starter

    Thanks! :)

    I did a little more research and now have some more questions.


    steve108 said:
    HedgeToaster, hello and welcome to TF ,

    Get a second opinion using HD Sentinel app.
    Thanks for the suggestion. HD Sentinel does cost money though - or are you talking about the free trial?

    jumanji said:

    The short answer is if the Current Pending Sectors count keeps increasing, it would mean that [...] the backups you do on such a drive are no longer relliable.

    The Current Pending Sector count increasing only applies to the 1TB drive; for the 8TB drive it is too early to tell since I caught it early and stopped using the drive right away after noticing it.

    So I guess that answers my question of viability for the 1TB drive, but what about the 8TB drive?

    1) What's the chance of the 8TB drive getting Pending Sectors just a week after backing up data from another drive afflicted by them? And that it seems the folder most likely containing the Pending Sectors on the 8TB drive may very well be the backup-copy of that same folder afflicted by them on the 1TB drive?

    It just seems a little too unlikely to be a coincidence to me.

    Could this be a false-positive error detection somehow?


    If the 1TB drive is a lost cause, that's not so bad, I guess.

    Losing the 8TB drive as a viable backup-drive on the other hand would mean I'd need to buy two new hard drives, not just one. So I still hope the 8TB drive can be fixed. o_O

    I've heard several methods to "fix" Pending Sectors:

    - chkdsk (high risk of deleting files)
    - formatting the drive (last resort; also awkward since I need to write the exact same data back to it afterwards)
    - writing zeroes to the remaining disk space (really?? how does that help here?)

    Keep in mind I didn't run any troubleshooting methods like chkdsk yet - since I've heard chkdsk will delete files, so any such measure can't be taken until after evacuating my data first.


    2) So let's say that, after backing everything up to a new hard drive, I try one of those methods, and, hypothetically, this reduces Crystal Disk Info's Pending Sector count down to 0. What would that say about the future reliability of the 8TB drive?


    3) Also, I've read that Pending Sectors can either be "logical errors" (not so bad, I guess?), or actual physical damage on the hard drive which can spread when trying to read/write in the already damaged area. (I'm imagining something like a "tear" getting bigger, I suppose.)

    I'm guessing the 1TB drive has physical damage, since the Pending Sector count got bigger when interacting with one specific folder, even just from calculating its combined file size. I don't know about the 8TB drive (yet) though.

    Asking in general: Would it be possible to stop physical damage from getting worse in the future by somehow preventing the hard drive from ever reading/writing in the damaged sectors? (and maybe some of the "surrounding" sectors?)

    Also, how would I do that? Would chkdsk marking these sectors as "bad" be enough to stop it from accessing them again in the future?

    Or could I partition them off and just never read that partition? (This sounds more complicated.)


    4.1) 1TB drive: How "bad" are 15 Pending Sectors anyway? As in: There aren't hundreds of them, "just" 15 so far? How bad is that? 1 Sector = 512 byte, so 15 bad sectors = 7,5 kb are damaged? That... doesn't sound so bad? (Unless it exactly hits the hard drive's file table, I guess. What's the chance of that, btw?)

    4.2) 8TB drive: How "bad" are 8 Pending Sectors / 8 Uncorrectable Sectors, which had not been there just one week earlier?

    Again, without Crystal Disk Info, I wouldn't even have noticed anything was wrong. No obviously broken files, I mean, though I probably just didn't find them yet. And, again, I didn't run chkdsk yet either.


    5) Also, and this is important:

    Is there anything I can do to prevent the Pending Sector issue from getting worse while I'm evacuating my data?

    I'll have to re-parse the entire drives fully, and probably more than once to verify data consistency with the new backup (using "compare file contents"-mode).

    I'd really rather not be in the middle of the backup only for the issue to get worse, possibly damaging additional files. o_O


    6) Furthermore, is there a way for me to find out which files have been damaged, since then I can try to recover them from elsewhere? (Either online, or from backup)


    Thanks in advance for any help provided.

    Apologies if I don't respond immediately.
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  7. Posts : 21,421
    19044.1586 - 21H2 Pro x64

    I was suggesting the free version of HD Sentinel.
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  8. Posts : 1,621
    Windows 10 Home

    All I know is: a couple of times HDS (I have the paid version, free does work fine though), went from "Green, all HDDs aok" for a long time, suddenly went to "Yellow alert" (sorry, my ST-TNG coming through) on one of my hybrid HDDs. Sector reallocation count and whatelse. Right after my 2nd routine backup onto twin ext usb HDDs, HDS reported "red alert". From what I read, such can happen in a matter of hours or days or weeks or months. No rhyme, no reason, that I know of. I quickly replaced the hybrid and continued on. When I see "yellow alert", I treat it like "red alert" to avoid data loss and OS functionality loss.
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  9. Posts : 1,621
    Windows 10 Home

    By any chance, is Windows or a 3rd party utility running defragment OPs in the background, and, by any chance, are one or both of those HDDs hybrids? Reason for asking: some hybrid HDDs do not take kindly to defragging, while some others do not mind at all. My two hybrid HDDs did mind, hence the "yellow" became "red" in short order. Very likely Jumanji probably can tell us if one or both of your HDDs are hybrids.
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  10. Posts : 32,107
    10 Home x64 (22H2) (10 Pro on 2nd pc)

    HedgeToaster said:
    The only noteworthy things I did on that drive in that week were:
    a) Running a program which created 5000+ empty directories in a fairly short time as the by-product of a test. (I don't know if something like that can cause problems?)
    A Pending sector is not necessarily a bad sector.....

    Bree said:
    They are not necessarily bad sectors, but they are 'pending' a test by the drive's internal controller to confirm whether or not they are bad. Only when they have been tested and confirmed as bad will they be replaced by a sector from a spare pool unused sectors, set aside for this purpose. When a bad sector is replaced like this the Pending Sector Count will go down by one, and '05. Reallocated Sector Count' will go up by one.

    If on the other hand all the sectors are tested and found to be good then the Pending Sector Count will reset to zero an no sectors will be reallocated.

    A sector cannot be tested while it is in use. To force the drive's controller to test all sectors you can do a Full format (not a Quick format). That would take a long time on an 8TB drive, plus you'd have to back up all your files first.

    After a full format you should have no more pending sectors. If the Reallocated Sector Count has gone up then they have been tested and found to be bad, if it is still zero then all 'pending' sectors have been found to be good.

    False positives for Pending Sector Count have sometimes been reported elsewhere as being associated with writing a Torrent to the drive. Seems it may push some drives a bit too hard and for too long, causing some sector errors. These would be marked as 'pending' for later testing, but may well turn out to have been good sectors after all.
    Newish 8TB HDD Shows Health Status (Caution) - post #12

    It is probably no coincidence that the OP of that thread had exactly the same model of drive as you have. They later reported that....

    Billy Ball said:
    I used SeaTools Bootable to attempt to 'fix' the bad sectors and CrystalDiskInfo / Hard Disk Sentinel now show a perfectly healthy HDD. Should I still be worried though?
    Newish 8TB HDD Shows Health Status (Caution) - post #14

    Bree said:
    In this case the Pending Sectors seem to have been tested, found to be good, and the Pending Sector Count reset to zero.

    That is an encouraging sign, but I'd keep an eye on this drive just in case.
    Newish 8TB HDD Shows Health Status (Caution) - post #21

    Read the whole of that thread, then make your own mind whether to attempt a reformat, and whether to trust it in future should the Pending Sector Count be successfully reset.

    @Billy Ball has not been back on Ten Forums since Nov. 2020, but if they see this, perhaps they could say how their drive has been since then....
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