Re: sync()

Tom Lane wrote:
> Tatsuo Ishii <t-ishii(at)sra(dot)co(dot)jp> writes:
> >> What we really need is something better than sync(), viz flush all dirty
> >> buffers to disk *and* wait till they're written. But sync() and sleep
> >> for awhile is the closest portable approximation.
>
> > Are you saying that fsync() might not wait untill the IO completes?
>
> No, I said that sync() might not. Read the man pages. HPUX's man
> page for sync(2) says
>
> sync() causes all information in memory that should be on disk to be
> written out.
> ...
> The writing, although scheduled, is not necessarily complete upon
> return from sync.

Yep, BSD/OS says:

BUGS
Sync() may return before the buffers are completely flushed.

At least they classify it as a bug.

--
Bruce Momjian | http://candle.pha.pa.us
pgman(at)candle(dot)pha(dot)pa(dot)us | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073