If you have a S.M.A.R.T. monitored disk and get "unreadable (pending) sectors" or "failed command: READ FPDMA QUEUED" or "Offline uncorrectable sectors" errors or such, here's how to find out which file system blocks and files are affected, and how to force the about to be failing disk to reallocate (map out) those sectors:
https://www.smartmontools.org/wiki/BadBlockHowto

#SMART #smartmontools #smartd #smartctl #tune2fs #badblocks #debugfs #dd