HP-UX Reference (11i v2 04/09) - 2 System Calls (vol 5)

sync(2) sync(2)

NAME

sync - update disk

SYNOPSIS

#include <unistd.h>

void sync(void);

DESCRIPTION

sync() causes all information in memory that should be on disk to be written out. This includes

modiﬁed ﬁle system meta-data and delayed block I/O.

It should be used by commands and programs that examine a ﬁle system, such as

fsck, df, etc. It is

mandatory before a shutdown.

The writing, although scheduled, is not necessarily complete upon return from sync .

In some HP-UX systems,

sync() may be reduced to a no-op. This is permissible on a system which

does not cache buffers, or in a system that in some way ensures that the disks are always in a consistent

state.

AUTHOR

sync() was developed by HP and AT&T Bell Laboratories.