A. If you're using software RAID 5, you have three or more dynamic disks configured as a single fault-tolerant volume that data and parity information is stored on. If you lose a single disk from the set, no data is lost thanks to the data and parity information on the remaining disks, which can be used to calculate the data on the lost disk. If you need to replace a disk (like I just did after one of my Western Digital Black drives died after six months), follow the procedure below:

  1. Replace the dead disk with a new on in the server.
  2. Access the Disk Management node of Server Manager.
  3. Your replacement disk will be found and you'll be prompted to initialize the disk.
  4. Once it's initialized, right-click the disk and select Convert to Dynamic Disk...
    Fixing a RAID 5 array
  5. Ensure that only your new disk is selected to convert and click OK.
  6. Scroll down to the disk that's missing for your RAID 5 set, right-click it, and select Repair Volume...
    Fixing a RAID 5 array
  7. Your new disk will be listed to be used as the replacement. Make sure it's selected and click OK.
    Fixing a RAID 5 array
  8. Your RAID 5 volume will now go into a Resyncing state, which can take a long time—it has to repopulate the data/parity information on the new disk to make the RAID 5 volume fault tolerant again. Right-click the missing disk, which no longer has any associated volume, and select Remove Disk.
    Fixing a RAID 5 array

Try and minimize the workload on the RAID 5 while it's resyncing because a heavy load will slow down the rebuild.