.\" Copyright (c) 1980, 1991, 1993
.\" The Regents of the University of California. All rights reserved.
.\" %sccs.include.redist.man%
.\" @(#)sync.2 8.1 (Berkeley) %G%
.Nd "synchronize disk block in-core status with that on disk"
function forces a write of dirty (modified) buffers
in the block buffer cache out
to disk. The kernel keeps this information in core to reduce
the number of disk I/O transfers required by the system.
As information in the cache is lost after a system crash a
(about every 30 seconds).
may be used to synchronize individual file descriptor
may return before the buffers are completely flushed.
function call appeared in Version 6 AT&T UNIX.