Skip to main content
NetApp Knowledge Base

What is a persistent cache backup device failure?

  1. Last updated
  2. Save as PDF
Views:
1,971
Visibility:
Public
Votes:
1
Category:
e-series-systems
Specialty:
esg
Last Updated:

​ ​ ​  

Applies to

All E-Series platforms

Answer

If a diagnostic test for a persistent cache backup device fails, then the device is considered unusable. All volumes will change to write-through caching whenever the usable capacity of the persistent cache backup device is less than that of the cache memory. 

  • This will generate a recovery failure entry stating that there is insufficient cache backup device capacity
  • Volumes configured to allow write caching without batteries will be unaffected

Note: It is possible (although unlikely to occur) that losing a persistent cache backup device will not cause the usable capacity of persistent storage to fall below the usable capacity of cache memory. In this case, cache will be unaffected.

Additional Information

Replacement of the controller posting the error will be necessary to resolve the issue.

NetApp provides no representations or warranties regarding the accuracy or reliability or serviceability of any information or recommendations provided in this publication or with respect to any results that may be obtained by the use of the information or observance of any recommendations provided herein. The information in this document is distributed AS IS and the use of this information or the implementation of any recommendations or techniques herein is a customer's responsibility and depends on the customer's ability to evaluate and integrate them into the customer's operational environment. This document and the information contained herein may be used solely in connection with the NetApp products discussed in this document.