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What is the behavior of controller firmware when replacing a bypassed drive?

Last Updated:

Applies to

E-Series Controller Firmware 7.xx


The manner in which controller firmware handles bypassed drives was changed in 7.xx controller firmware. In the case of physically replacing a bypassed drive, implementation of tracking drives by their WWN (instead of based on the slot), and the ability to reconstruct individual drive pieces to handle late drive check-in, has caused failures that were not handled gracefully by controller firmware.

The default 07.xx controller firmware drive replacement behavior is as follows:

  • If a drive is bypassed on both ports, it will reconstruct its affected pieces to a HotSpare upon a failed write.
  • The drive is not failed by Controller Firmware.
  • The firmware still retains knowledge that the drive that is bypassed exists, and it believes it to be in an optimal sate.
  • If the drive is physically removed, it is not failed by controller firmware but will be marked as not present/optimal.

Upon insertion of a replacement drive to the same enclosure/slot, the new drive is seen as unassigned. As drives are tracked by their WWN, and the original drive was never failed, the controller firmware is still looking for its existing not present/optimal drive to be reinserted into the system to CopyBack  from the HotSpare .

The remnant entry for the not present/optimal drive cannot be failed by the GUI. The user will have to manually intervene by running a CLI script to replace the drive and then CopyBack  will occur to the new drive. This behavior was later changed so that when another drive is inserted in place of the missing drive, controller firmware performs a copy back to that drive and reconstructs failed pieces on that drive. This is regardless of whether the inserted drive is new, unassigned, or assigned. The inserted drive essentially replaces the missing drive in the drive group. This change was implemented in the following controller firmware code levels.

Dell and Teradata Only:

  • 07.60.xx.xx and later
  • 07.35.xx.xx and later
  • 07.36.03.x0 and later

IBM and Generic releases:

  • 07.75.xx.xx and later
  • 07.70.33.x0 and later
  • 07.60.51.x0 and later
  • 07.35.62.x0 and later

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