I have a four disk RAID 5 array that is in the process of failing hard. One disk is completely dead and
smartctl is telling me that a second disk is failing. All the data on the RAID is backed up, however about 1 TB is non trivial to restore since it is ripped CDs and DVDs and I would have to rip them again. I have a spare disk that I can swap out for the dead drive and attempt to rebuild, if that is the right term, the RAID and then backup the difficult data to a different fully healthy new RAID 6 setup. I could also backup the data from the now non-redundant RAID directly to the new RAID.
Is is gentler on a disk from a non-redundant four disk RAID to "restore" the RAID or copy the data directly.
The disks are 2 TB each giving a total RAID size of 6 TB. There is about 5 TB of data on the RAID and I would want to get 1 TB off of it.