Comment by pajko

Without any more information this post is just bullshit. For example, it's not documented how the flushing has been done. On Linux, even issuing 'sync' is not enough: https://unix.stackexchange.com/questions/98568/difference-be...

The bottom answer especially states that "blockdev --flushbufs may still be required if there is a large write cache and you're disconnecting the device immediately after"

The hpdarm utility has a parameter for syncing and flushing device buffers themselves. Seems like all three should be done for a complete flush at all levels.