On 14/12/17 18:57, Warren Young wrote:
On Dec 13, 2017, at 5:15 PM, J Martin Rushton martinrushton56@btinternet.com wrote:
# dd if=/dev/sdc of=/home/dd-copy-of-sdc
Better, use ddrescue:
https://www.gnu.org/software/ddrescue/
dd will do unfortunate things like quit early on I/O errors, even if later blocks would read just fine. ddrescue assumes the input file is dodgy and tries to cope.
Looks interesting. I've only used dd in anger, and then only maybe 3 or 4 times over the last 20 years. It's worth pointing out that ddrescue is not in the main distro, you'll need to get it from EPEL.
Whatever method you use though: "Be diligent because every time a physically damaged drive powers up and is able to output some data, it may be the very last time that it ever will." (ddrescue manual section 9)