diff --git a/share/man/man4/Makefile b/share/man/man4/Makefile index 42439d4d8aa..8650d5ef58d 100644 --- a/share/man/man4/Makefile +++ b/share/man/man4/Makefile @@ -13,9 +13,9 @@ MAN4= adv.4 adw.4 aha.4 ahb.4 ahc.4 amd.4 amr.4 an.4 ata.4 atkbd.4 \ ppbus.4 ppc.4 ppi.4 ppp.4 psm.4 pt.4 pty.4 rl.4 \ route.4 sa.4 sbc.4 screen.4 scsi.4 \ sd.4 ses.4 sf.4 si.4 sio.4 sis.4 sk.4 sl.4 smb.4 smbus.4 smp.4 snp.4 \ - splash.4 sppp.4 st.4 ste.4 stf.4 sym.4 syscons.4 sysmouse.4 tcp.4 \ - termios.4 ti.4 tl.4 ttcp.4 tty.4 tun.4 twe.4 udp.4 udbp.4 uhci.4 \ - ukbd.4 umass.4 ums.4 unix.4 update.4 urio.4 usb.4 vga.4 vinum.4 vn.4 \ + splash.4 sppp.4 st.4 ste.4 stf.4 sym.4 syncer.4 syscons.4 sysmouse.4 \ + tcp.4 termios.4 ti.4 tl.4 ttcp.4 tty.4 tun.4 twe.4 udp.4 udbp.4 uhci.4 \ + ukbd.4 umass.4 ums.4 unix.4 urio.4 usb.4 vga.4 vinum.4 vn.4 \ vpo.4 vr.4 wb.4 wi.4 wx.4 worm.4 xl.4 xpt.4 yp.4 zero.4 MLINKS= ata.4 acd.4 ata.4 ad.4 ata.4 afd.4 ata.4 ast.4 diff --git a/share/man/man4/update.4 b/share/man/man4/syncer.4 similarity index 60% rename from share/man/man4/update.4 rename to share/man/man4/syncer.4 index 8a16a248287..0d8a84f7267 100644 --- a/share/man/man4/update.4 +++ b/share/man/man4/syncer.4 @@ -1,8 +1,5 @@ -.\" Copyright (c) 1996 -.\" Mike Pritchard . All rights reserved. -.\" -.\" Copyright (c) 1991, 1993 -.\" The Regents of the University of California. All rights reserved. +.\" Copyright (c) 2000 Sheldon Hearn +.\" All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions @@ -12,13 +9,6 @@ .\" 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 @@ -34,38 +24,42 @@ .\" .\" $FreeBSD$ .\" -.Dd February 11, 1996 -.Dt UPDATE 4 -.Os FreeBSD +.Dd July 14, 2000 +.Dt SYNCER 4 +.Os .Sh NAME -.Nm update -.Nd flush internal filesystem caches to disk periodically +.Nm syncer +.Nd filesystem synchronizer kernel process .Sh SYNOPSIS -.Nm update +.Nm syncer .Sh DESCRIPTION The -.Nm update +.Nm kernel process helps protect the integrity of disk volumes -by flushing -volatile cached filesystem data -to disk. This is done at thirty second intervals by default. -The time period may be changed by using -.Xr sysctl 8 -to modify the -.Va kern.update -variable. -The -.Nm update -process does the equivalent of the -.Xr sync 2 -function call to do the task. +by flushing volatile cached filesystem data to disk. +This is done at thirty second +.Pq actually Dv SYNCER_MAXDELAY - 2 +intervals by default. +.Pp +The kernel places all +.Xr vnode 9 Ns 's +in a number of queues equal to +.Dv SYNCER_MAXDELAY . +The +.Nm +process works through the queues +in a round-robin fashion, +usually processing one queue per second. +For each +.Xr vnode 9 +on the queue, +the +.Nm +process forces a write out to disk of its dirty buffers. .Sh SEE ALSO .Xr sync 2 , .Xr fsck 8 , -.Xr init 8 , -.Xr rc 8 , -.Xr sync 8 , -.Xr sysctl 8 +.Xr sync 8 .Sh BUGS It is possible on some systems that a .Xr sync 2 @@ -73,14 +67,16 @@ occurring simultaneously with a crash may cause file system damage. See .Xr fsck 8 . .Sh HISTORY -An -.Nm update -command appeared in +The +.Nm +process is a descendant of the +.Sq update +command, which apeared in .At v6 , and was usually started by .Pa /etc/rc when the system went multi-user. A kernel initiated -.Nm update +update process first appeared in .Fx 2.0 .