When upgrading from 7.7x.xx.xx firmware to the 7.83.18.00 firmware, the upgrade completes successfully, but an “Insufficient Cache Backup Device” message in the Recovery Guru may be logged. Other messages in the Recovery Guru such as “Write Cache Has Been Forcibly Disabled” may also be logged. If these messages appear, write cache will be disabled which will affect the performance of the subsystem. This problem does not cause data access or data loss issues. This behavior has only been seen on some firmware upgrades of the DS3500 Storage Subsystem.
The system may be any of the following IBM servers:
- IBM System Storage DS3512, type 1746, any model
- IBM System Storage DS3524, type 1746, any model
The following system firmware level(s) are affected:
This tip is not option specific.
The 7.83.18.00 firmware for the DS3500 is affected.
This tip is not Operating System specific.
The system has the symptom described above.
This behavior will be corrected in a future release of the 7.83 firmware.
See more details here