Francisco Javier Cabello Torres
I am trying to disable write cache but it's not working.
I have tried with several hard disks without success.
I have tried with version is 5.3 and 6.1 but it still not working.
Thanks in advance
That's how it's done, and it is permanent until overridden.
But be wary of your system startup scripts -- they may include their own call to hdparm to turn it back on again (which is what most people really do want).