HP Array Controller HSG V8.7 Software - Manual (Page 414)

B–142 HSG80 User’s Guide
Note The controller may take up to five minutes to flush data
contained within the write-back cache when you specify the
NOWRITEBACK_CACHE switch.
Example
This example shows how to enable write protect and turn off the read
cache on unit D102:
SET D102 WRITE_PROTECT NOREAD_CACHE
See also
SHOW UNITS
SHOW unit-number