SYNC(2) AerieBSD 1.0 Refernce Manual SYNC(2)

NAME

sync — "synchronize disk block in-core status with that on disk"

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 in-kernel process update(8) (about every 30 seconds).

The function fsync(2) may be used to synchronize individual file descriptor attributes.

SEE ALSO

fsync(2), sync(8), update(8)

HISTORY

A sync(); function call appeared in Version 2 AT&T UNIX.

BUGS

sync(); may return before the buffers are completely flushed.

AerieBSD 1.0 Reference Manual August 26 2008 SYNC(2)