Skip to main content
NetApp Knowledge Base

E-Series: Write back caching forcibly disabled alert

Last Updated:

Applies to

NetApp E-Series


This article describes the procedure to troubleshoot "Write-Back Caching Forcibly Disabled" on E-Series systems.

Write-back caching was disabled on one or more volumes. This problem can occur for the following reasons:

  • Battery Failure
  • Battery below minimum capacity
  • The cache size memory of the controllers are different
  • Cache Reconfiguration 
  • A Cache Data-Restore operation is in progress, which interrupted the normal write-back caching process
  • The space in the cache backup device is insufficient for storing the cache
  • Memory parity error
  • Simplex configuration - cache cannot be mirrored

Important Notes

  • When write-back caching is enabled when volumes are configured, write-back caching improves I/O performance. When write-back caching is disabled, the system goes into write through mode, meaning that the I/O will get acknowledged after it is written to disk rather than when it is written to cache. In such case, I/O performance to the volume or group of volumes can be seriously degraded depending on the drives. 
  • The error triggers a critical event. 
  • The controller is in the Notified state. When write-back caching is enabled, the system transitions from Notified to Optimal after all volumes configured to use write-back caching are restored. 
  • When the system transitions from Notified to Optimal, an information MEL event is logged to show that all normal write-back caching capabilities are restored for all volumes in the system. 
  • While in the Notified state, a forced-disable of write-caching on any additional volumes has no effect, and no state transition occurs. 


Scan to view the article on your device

Registered NetApp customers get unlimited access to our dynamic Knowledge Base.

New authoritative content is published and updated each day by our team of experts.

Current Customer or Partner?

Sign In for unlimited access

New to NetApp?

Learn more about our award-winning Support