=> show

Smart Array P400 in Slot 4
   Bus Interface: PCI
   Slot: 4
   Serial Number: P61630K9SW20DU
   Cache Serial Number: PA82C0J9SWG601
   RAID 6 (ADG) Status: Disabled
   Controller Status: OK
   Chassis Slot:
   Hardware Revision: Rev D
   Firmware Version: 5.20
   Rebuild Priority: Medium
   Expand Priority: Medium
   Surface Scan Delay: 3 secs
   Surface Scan Mode: Idle
   Post Prompt Timeout: 15 secs
   Cache Board Present: True
   Cache Status: OK
   Accelerator Ratio: 100% Read / 0% Write
   Drive Write Cache: Enabled
   Total Cache Size: 256 MB
   No-Battery Write Cache: Disabled
   Battery/Capacitor Count: 0
   SATA NCQ Supported: True

=> ctrl slot=4 modify cacheratio=100/0

Error: "cacheratio=100/0" is not a valid option for Smart Array P400 in Slot 4

   There are no options currently available.

=> ctrl slot=4 modify cacheratio=50/50

Error: "cacheratio=50/50" is not a valid option for Smart Array P400 in Slot 4

   There are no options currently available.

=>