I have a drive that has had a few file corruptions. It seems to be due to getting very hot at some point in the past, the max reported temperature is 99C ! I've recovered as much data from it as I can with ntfsclone --rescue and mounted the image.
The reallocated sector count is zero but the current pending sector count is 233. I have read every sector on the drive (single partition) with the data recovery process but the drive has not changed the pending sector count. I find this strange, I thought that the drive should remap the pending sectors or decide they are fine.
I'm currently running a format with bad block checking on, the kernel is reporting i/o errors in the same blocks as before but still the drive is not reallocating sectors or changing the count. The output from the format is as follows:
mke2fs 1.41.14 (22-Dec-2010)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
61054976 inodes, 244190000 blocks
12209500 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=4294967296
7453 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968,
102400000, 214990848
Checking for bad blocks (read-only test): 11.06% done, 55:05 elapsed