Enabling Exadata Write-back in Oracle Support Note ID 1500257.1.

WriteThrough FlashCache:

·         To reinstate Writethrough caching, FlashCache must first be flushed. 

·         FlashCache must then be dropped and cellsrv stopped.

CELLCLI> alter flashcache all flush

CELLCLI> drop flashcache
CELLCLI> alter cell shutdown services cellsrv

CELLCLI> alter cell flashCacheMode = WriteThrough

CELLCLI> alter cell startup services cellsrv

CELLCLI> list metricdefinition attributes name, description where name like '.*_DIRTY‘

Write Back mode

CellCLI> drop flashcache
CellCLI> alter cell shutdown services cellsrv
CellCLI> alter cell flashCacheMode = WriteBack
CellCLI> alter cell startup services cellsrv
CellCLI> create flashcache all

Exadata Smart Flash Cache write-back architecture