Drive Logical States

  1. Online - The device is available and operating normally.
  2. Offline - The drive is currently not online and not participating in user IO. The offline device can be connected and made available for low-level IO. While the RAID metadata can be read from or written to the offline drive, it is not recognized as being logically ready for the RAID user's IO.
  3. Need Reconstruction (need_recon) - The drive data area is partially or fully incorrect and needs reconstruction from other drive data and parity. The drive can still participate in user IO operations when it requires reconstruction.
  4. Reconstructing - The drive data is being reconstructed. The drive can participate in user IO while reconstructing.