2 files changed, 74 insertions, 1 deletions

diff --git a/share/man/man4/Makefile b/share/man/man4/Makefile
index ff41e7fb6c3e..c15d1d6df90d 100644
--- a/share/man/man4/Makefile
+++ b/share/man/man4/Makefile
@@ -5,7 +5,7 @@ MAN4=	bpf.4 cd.4 ch.4 clnp.4 cltp.4 ddb.4 drum.4 esis.4 fd.4 fpa.4 \
 	lkm.4 lo.4 netintro.4 ns.4 \
 	nsip.4 null.4 pt.4 pty.4 route.4 \
 	scsi.4 sd.4 snp.4 spp.4 st.4 su.4 tcp.4 \
-	ttcp.4 termios.4 tp.4 tty.4 udp.4 uk.4 unix.4 worm.4 yp.4
+	ttcp.4 termios.4 tp.4 tty.4 udp.4 uk.4 update.4 unix.4 worm.4 yp.4
 MLINKS+=fd.4 stderr.4 fd.4 stdin.4 fd.4 stdout.4
 MLINKS+=netintro.4 networking.4
 MLINKS+=ipfirewall.4 ipacct.4 ipfirewall.4 ipfw.4 ipfirewall.4 ipaccounting.4
diff --git a/share/man/man4/update.4 b/share/man/man4/update.4
new file mode 100644
index 000000000000..f78fcef1c04b
--- /dev/null
+++ b/share/man/man4/update.4
@@ -0,0 +1,73 @@
+.\" Copyright (c) 1996
+.\"	Mike Pritchard <mpp@FreeBSD.org>.  All rights reserved.
+.\"
+.\" Copyright (c) 1991, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"	This product includes software developed by the University of
+.\"	California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.Dd February 11, 1996
+.Dt UPDATE 4
+.Os FreeBSD
+.Sh NAME
+.Nm update
+.Nd flush internal filesystem caches to disk frequently
+.Sh SYNOPSIS
+.Nm update
+.Sh DESCRIPTION
+The
+.Nm update
+kernel process helps protect the integrity of disk volumes
+by flushing
+volatile cached filesystem data
+to disk at thirty second intervals.
+.Nm Update
+does the equivalent of the 
+.Xr sync 2
+function call to do the task.
+.Sh SEE ALSO
+.Xr sync 2 ,
+.Xr fsck 8 ,
+.Xr init 8 ,
+.Xr rc 8 ,
+.Xr sync 8
+.Sh BUGS
+It is possible on some systems that a
+.Xr sync
+occurring simultaneously with a crash may cause
+file system damage. See
+.Xr fsck 8 .
+.Sh HISTORY
+An
+.Nm update
+command appeared in
+.At v6 ,
+and was usually started by /etc/rc when the system went multi-user.
+.Nm Update
+was turned into a kernel initiated process in FreeBSD 2.0.