Exadata CELL Flash Cache Drop Recreate

One exadata CELL had strange flash card io statistics as below.
It was not using the card.
Rebooting CELL service or rebooting cell server did not made any change.

# iostat -xn 1 
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz avgqu-sz await r_await w_await svctm %util
nvme1n1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

So, we dropped and recreated flashcache as below, than it started using that flash disk very well.
If below procedure was also not successfull, only solution would of course be card replacement.

	#### BEFORE - control commands

	cellcli>list griddisk
	cellcli>list flashcache detail 

	#### drop-recreate procedure

	CellCLI>drop flashcache all 
	CellCLI>drop flashlog all 
	CellCLI>drop celldisk all flashdisk 
	CellCLI>create celldisk all flashdisk 
	CellCLI>create flashlog all size=480M 
	CellCLI>create flashcache all 


	#### AFTER - control commands
	cellcli>list griddisk
	cellcli>list flashcache detail