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I have a WD 2TB drive, a good 10 years old now. Needless to say it has been slowly failing, and getting slower. After testing and determining that the long response times are unfixable, I moved all my data to a new drive, then I long formatted the drive.

I probably should have checked just before moving all my data to a new drive, but I loaded up Crystal Disk Info, and here are the results

I'm a little confused about the discrepancy between the highlighted drive results and the listed results below, but not only am I inclined to trust the highlighted results, but on the safer side they are higher. If anyone could explain the discrepancy, I'd also appreciate it. Anyways, my actual questions are:

  1. I long formatted (all zeroes) the drive, why are there still pending sectors? As I understand, those are sectors that the drive will stop using when it has a backup sector to write that sector's data to. But if it is all zeroes, it shouldn't have to reallocate that sector.

  2. The total amount of bad sectors (reallocated, pending, and uncorrectable sectors) is 1148, which comes out to 574 MB (out of 2 TB). I know that any bad sectors means that more are likely to come, however this drive has had bad sectors for a long time, and I'd like to use it as a temporary backup for my main drive so I can reinstall windows. If I understand correctly, not reading or writing to the drive often will make its last sectors last much longer.

However, new that I formatted the drive, it reports that 210 MB are taken up. I assume that it reports the bad sectors as used up, but that value is much smaller than I'd expect. Is the missing 364 MB the extra sectors on the drive, or did I make a mistake in assuming 512 bytes per sector? Also, would anyone have experience on how fast the remaining sectors will fail? Since only half a percent of the sectors have failed, I once again assume that the drive isn't quite on the brink of death that it first appears.

2 Answers2

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The total amount of bad sectors (reallocated, pending, and uncorrectable sectors) is 1148, which comes out to 574 MB [...]

I assume that it reports the bad sectors as used up, but that value is much smaller than I'd expect.

Your calculations are off by a thousand. Since a sector is 512 bytes, the total is actually 574 kB or about half a megabyte. (Although some disks come with 4 kB sectors, making it 4592 kB.)

Also reallocated sectors on magnetic HDDs are not actually "used up" or removed from your total space – their sector numbers been actually reassigned to a different physical location. All disks have a small amount of spare space reserved for this purpose which is not originally part of the total available space, with the reallocation being managed by the disk's firmware independently from any OS-level "formatting".

More likely that the ~200 MB is actually in use by the filesystem metadata, such as the master file table and the space bitmap. 0.1% of the total space sounds about usual for NTFS.

grawity
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At a certain stage the state may plausibly be such that the prior damage has mechanically damaged the surface of the disk, i.e. material has come lose and is spreading inside the box, causing new damage.

There is no way to recover from this state; scrap the disk.

Hannu
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