Hi,

I think your better off doing the DD method, you can export and import a PG at a time (ceph-objectstore-tool)

But if the disk is failing a DD is probably your best method.

In case of hardware problems or broken sectors, I would recommend 'dd_rescue' instead of dd. It can handle broken sectors, automatic retries, skipping etc.

You will definitely need a second disk to rescue to.

Regards,

Burkhard