While checking on the log files for the hitachi 500Gb hard drive, I saw 2 interesting attributes: Reallocated sector count and Current pending sector count.
Reallocated sector count
From wikipedia: When the hard drive finds a read/write/verification error, it marks this sector as "reallocated" and transfers data to a special reserved area (spare area). This process is also known as remapping, and "reallocated" sectors are called remaps. This is why, on modern hard disks, "bad blocks" cannot be found while testing the surface – all bad blocks are hidden in reallocated sectors. However, as the number of reallocated sectors increases, the read/write speed tends to decrease. The raw value normally represents a count of the number of bad sectors that have been found and remapped. Thus, the higher the attribute value, the more sectors the drive has had to reallocate.
Current pending sector
From wikipedia: Number of "unstable" sectors (waiting to be remapped, because of read
errors). If an unstable sector is subsequently written or read
successfully, this value is decreased and the sector is not remapped.
Read errors on a sector will not remap the sector (since it might be
readable later); instead, the drive firmware remembers that the sector
needs to be remapped, and remaps it the next time it's written.
Time to backup data and to get a new hard drive soon.
- wong chee tat :)
