--On Monday, November 23, 2020 4:46 PM +0100 Simon Matter <simon.matter at invoca.ch> wrote: > I suggest to "mdadm --fail" one drive, then "mdadm --remove" it. After > replacing the drive you can "mdadm --add" it. Does it make sense to dd or ddrescue from the removed drive to the replacement? My md RAID set is on primary partitions, not raw drives, so I'm assuming the replacement drive needs at least the boot sector from the old drive to copy the partition data.