Been a long time, but thanks for the heads-up. In fact the backup was done by the supplier of the server, and never shared them with IT team due to their contractual agreements. And this issue happened when the agreement had expired and no longer had the supplier to help..
Finally swapping the faulty disk with a new one solved the issue, as being in RAID 1, the rebuilding process was done.
rproffitt commented: Thanks for the update. It does raise other questions about what is called the "Disaster Recovery Plan." +15