Read: I/O error

[Dmitri Feofilaktov]

Example of command:
$ cp sym_data02C3.dbf ../sym_data02C3.dbf
cp: bad copy to ../sym_data02C3.dbf: read: I/O error

stm utility show one read error on disk.

How can I check disk surface for errors?
fsck shows no errors on mounted filesystem or nonmounted logical volume.

PS. I understand, that I lost my data on this disk. I want to prevent future
errors.

[Zhang Zhao gui]

I think there are bad sectors in your disk. It usually happens when there is a
trend of growing defect list or just because of disk failure by accident due to
the power shutdown or current fluctuation/surge. You can run STM to check or
install Predictive Support Software to monitor your system. Now You may have
to replace the faulty disk or need to format this disk to mark the bad
sectors.

If it is a critical system I recommend you install Mirror disk to prevent
such events from happening again in the future and protect your important data.