@DELL-Joey C​ Thank you for answer, but I try to restart the controller - nothing change. It happens when I change BBU

What else can I do? Thank you

Hi,

Can you confirm what led to this issue, was there a controller replacement or the system hasn't been turned on for some time. 

The Storage Center’s Configuration Access (CA) subsystem essentially keeps consistency between the two Storage Center controllers. Subsystems "request" data from other subsystems with a CA Request. This can be between controllers or just between subsystems. Sometimes these CA Requests can get stuck where a subsystem isn’t responding to the request. For example, stuck CA Requests may be due to a cable issue or some upgrade steps done in the wrong order. Depending on the significance of the stuck CA Request, examples to clear them would be: simply deleting the request, restarting a check for Storage Center update, or a reboot of controller(s).

Hello,

Verify Controller Swap Status

If the BBU was replaced without clearing the controller swap status:

• Open Dell Storage Manager (DSM).
• Navigate to the Hardware tab.
• Clear the controller swap status.
• Reboot the controller.

This step is documented in the Dell SC5020 Controller Battery Replacement Guide
View the Transcript for the text:

https://www.dell.com/support/contents/en-lc/videos/videoplayer/how-to-replace-controller-battery-for-storage-sc5020-and-scv3000-series/6079815179001

Seeing that the controller has no users and is only accessible via __safemode__, it may have lost its configuration. In this case:

• You will need to restore configuration from the peer controller (if dual-controller setup) or from Dell Support.
• If both controllers are affected, Dell Support must be contacted to reload configuration manually.
• NOTE: Commands to recover configaccess are not publicly documented.