How should the DB_FLASH_CACHE_SIZE be configured to use both devices?

You have installed two 64G flash devices to support the Database Smart Flash Cache feature on
your database server that is running on Oracle Linux.
You have set the DB_SMART_FLASH_FILE parameter:
DB_FLASH_CACHE_FILE= ‘/dev/flash_device_1 ‘,’ /dev/flash_device_2’
How should the DB_FLASH_CACHE_SIZE be configured to use both devices?

A.
Set DB_FLASH_CACHE_ZISE = 64G.

B.
Set DB_FLASH_CACHE_ZISE = 64G, 64G

C.
Set DB_FLASH_CACHE_ZISE = 128G.

D.
DB_FLASH_CACHE_SIZE is automatically configured by the instance at startup.

Explanation:
* Smart Flash Cache concept is not new in Oracle 12C – DB Smart Flash Cache in

Oracle 11g.
In this release Oracle has made changes related to both initialization parameters used by DB
Smart Flash cache. Now you can define many files|devices and its sizes for “Database Smart
Flash Cache” area. In previous releases only one file|device could be defined.
DB_FLASH_CACHE_FILE = /dev/sda, /dev/sdb, /dev/sdc
DB_FLASH_CACHE_SIZE = 32G, 32G, 64G
So above settings defines 3 devices which will be in use by “DB Smart Flash Cache”
/dev/sda – size 32G
/dev/sdb – size 32G
/dev/sdc – size 64G
New view V$FLASHFILESTAT – it’s used to determine the cumulative latency and read counts of
each file|device and compute the average latency