A few days ago I by chance realized that the DVD-RW I had used for months to do
may backup was probably damaged: apparently it was not, because I could burn my
data onto it without problems; but when I tried to copy its content into a hard
disk I got I/O errors and some directories could not be copied.
The problem disappeared when I changed the DVD with a brand new one, but now I
feel not sure: how can I know when my actual backup DVD should in case be
damaged as well? Is there any tool for that?