Save to file

sfdisk -d /dev/sda > partitions

Restore from File and force

sfdisk --force /dev/sda < partitions

sfdisk -d /dev/sda | sfdisk /dev/sdb

Using smartctl

smartctl -i /dev/sda

cat /proc/mdstat

Do the Folloing for all partitions of the malfunctioning disk. Note that mark as faill is not necessary or even possible in case the disk is not detected anymore from the OS.

Mark partition as failed

mdadm --manage /dev/md0 --fail /dev/sda1

Remove Partition

mdadm --manage /dev/md0 --remove /dev/sda1

Repeat for all required partitions

mdadm --manage /dev/md0 --add /dev/sda1

Warning: select the correct physical disk (/dev/sda in example) <sxh bashdd if=/dev/zero of=/dev/sda bs=512 count=8196 dd bs=512 if=/dev/zero of=/dev/sda count=8196 seek=$¹⁾</sxh>