sync(2)
NAME
sync, lsync − update super-block
SYNOPSIS
#include <unistd.h>
void sync(void);
void lsync(void);
DESCRIPTION
sync() causes all information in memory that should be on disk to be written out. This includes modified super blocks, modified inodes, 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.
In the HP Clustered Environment, sync() causes updates of all file systems in the cluster to be written out, while lsync() performs only a local sync(); that is, local buffers are flushed to disk and to remote nodes of the cluster, but remote nodes do not flush their own pages.
AUTHOR
sync() was developed by HP and AT&T Bell Laboratories. lsync() was developed by HP.
SEE ALSO
STANDARDS CONFORMANCE
sync(): SVID2, XPG2
Hewlett-Packard Company — HP-UX Release 9.0: August 1992