Matthew Kirkwood <matthew@hairy.beasts.org> writes:
> I had assumed that the overhead would come from synchronous
> metadata incurring writes of at least the inode, block bitmap
> and probably an indirect block for each syscall.
No Unix that I've ever heard of forces metadata to disk after each
"write" call; anyone who tried it would have abysmal performance.
That's what fsync and the syncer daemon are for.
regards, tom lane