NAS - Build a Linux NAS - Support recovering from a faulty disk

mdadm --detail /dev/md0

returns:

hdparm -i /dev/sdd | grep SerialNo

returns:

Model=ST16000NM001G-2KK103, FwRev=SB30, SerialNo=WL2091XL

Steps are:

• Wait until the disks has finished rebuilding on the spare disk if any.
• Power the server down.
• Replace the faulty disk.
• Power the server up again.
• Partition the disks.
• Add the new disk to the array with:

  mdadm --add /dev/md0 /dev/sdd1

sudo mdadm --manage /dev/md0 --add /dev/sdd1

If the original OS dies, but the RAID disks are okay, then rebuild a new OS.

Then, use mdadm to examine the superblock on one of the disks and use this to recover the raid:

mdadm --examine /dev/sda

returns:

Then use the listed UUID from the disk to assemble the raid onto the device md0:

mdadm --assemble /dev/md0 --uuid=<UUID>