sync —
force completion of pending disk writes (flush
cache)
The
sync utility can be called to ensure that
all disk writes have been completed before the processor is halted in a way
not suitably done by
reboot(8)
or
halt(8). Generally, it is
preferable to use
reboot(8) or
halt(8) to shut down the system,
as they may perform additional actions such as resynchronizing the hardware
clock and flushing internal caches before performing a final
sync.
sync utilizes the
sync(2) function.
fsync(2),
sync(2),
halt(8),
reboot(8)
A
sync command appeared in
Version 4 AT&T UNIX.
![[OpenBSD]](/openbsd.gif){kind=small}