Scanner Reporting erroneous Errors?

[muaddib]

I removed a fairly new 2TB Western Digital WD20EADS from my pool because scanner reported that it was damaged but when I ran WD's DLGDIAG Extended test everything was fine.  I re-installed the drive back into the pool and nothing appears to be wrong.  Any explanation for this?

[Christopher (Drashna)]

Depends on how Scanner was reporting it was damaged.

 

If it was the surface scan, running the WD diagnostic tools could have triggered the built in error correction routines and moved the affected files off of the damaged areas of the disk.  

This would be my guess.