From f5cb6bbd8493568cb028687d3c702d96457424fd Mon Sep 17 00:00:00 2001 From: jdolecek Date: Fri, 6 Oct 2000 19:54:26 +0000 Subject: [PATCH] update(8) is gone, put in some info about ioflush this addresses bin/11141 by Nick Hudson --- lib/libc/sys/sync.2 | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-) diff --git a/lib/libc/sys/sync.2 b/lib/libc/sys/sync.2 index 1aca75205f24..00ffbc40d21e 100644 --- a/lib/libc/sys/sync.2 +++ b/lib/libc/sys/sync.2 @@ -1,4 +1,4 @@ -.\" $NetBSD: sync.2,v 1.7 1999/12/02 21:42:40 kleink Exp $ +.\" $NetBSD: sync.2,v 1.8 2000/10/06 19:54:26 jdolecek Exp $ .\" .\" Copyright (c) 1980, 1991, 1993 .\" The Regents of the University of California. All rights reserved. @@ -52,13 +52,15 @@ 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 -.Fn sync -call is issued -frequently -by the user process -.Xr update 8 -(about every 30 seconds). +As information in the cache is lost after a system crash, +kernel thread +.Nm ioflush +ensures that dirty buffers are synced to disk +eventually. By default, a dirty buffer is synced after 30 seconds, +but some filesystems exploit +.Nm ioflush +features to sync directory data and metadata faster +(after 15 and 10 seconds, respectively). .Pp The function .Xr fsync 2 @@ -66,8 +68,7 @@ may be used to synchronize individual file descriptor attributes. .Sh SEE ALSO .Xr fsync 2 , -.Xr sync 8 , -.Xr update 8 +.Xr sync 8 .Sh BUGS .Fn sync may return before the buffers are completely flushed.