[CentOS] OT - Offline uncorrectable sectors

Mon Aug 25 10:36:00 UTC 2008
Stephen Harris <lists at spuddy.org>

On Mon, Aug 25, 2008 at 10:43:01AM +0200, Lorenzo Quatrini wrote:
> So again my question is:
> can I use dd to "test" the disk? what about
> dd if=/dev/sda of=/dev/sda bs=512
> Is this safe on a full running system? Has to be done at runlevel 1 or with a
> live cd?

Do not do this on a mounted filesystem; you risk corruption.  I'd be leary
of this command, though.

A better way is use the "badblocks" command; if you want to keep data
then "badblocks -n"; if you don't care about data then "badblocks -w".
Again, you can't do this on a mounted filesystem.