DragonFly On-Line Manual Pages


SYNC(2) 		 DragonFly System Calls Manual		       SYNC(2)

NAME

sync -- schedule filesystem updates

LIBRARY

Standard C Library (libc, -lc)

SYNOPSIS

#include <unistd.h> void sync(void);

DESCRIPTION

The sync() 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 sync() call is issued frequently by the user process syncer(4) (about every 30 seconds). The function fsync(2) may be used to synchronize individual file descrip- tor attributes.

SEE ALSO

fsync(2), syncer(4), sync(8)

HISTORY

A sync() function call appeared in Version 6 AT&T UNIX.

BUGS

Sync() may return before the buffers are completely flushed. DragonFly 4.1 June 4, 1993 DragonFly 4.1