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authorache <ache@FreeBSD.org>1994-11-02 10:04:11 +0000
committerache <ache@FreeBSD.org>1994-11-02 10:04:11 +0000
commitdcd5ec0ca701a90b9fdac91cc6d477c401bed547 (patch)
tree170aba8abc425199c8d4c4857200609464a0ddac /sbin/adjkerntz
parent3ced78a1134b86804c01a6fa46a59d15b6da2b0f (diff)
downloadFreeBSD-src-dcd5ec0ca701a90b9fdac91cc6d477c401bed547.zip
FreeBSD-src-dcd5ec0ca701a90b9fdac91cc6d477c401bed547.tar.gz
Restore back -i, -a
Diffstat (limited to 'sbin/adjkerntz')
-rw-r--r--sbin/adjkerntz/adjkerntz.831
1 files changed, 21 insertions, 10 deletions
diff --git a/sbin/adjkerntz/adjkerntz.8 b/sbin/adjkerntz/adjkerntz.8
index 1ddd72b..086f12a 100644
--- a/sbin/adjkerntz/adjkerntz.8
+++ b/sbin/adjkerntz/adjkerntz.8
@@ -30,21 +30,26 @@
.Nd "adjusts the kernel time if the machine runs wall CMOS clock"
.Sh SYNOPSIS
.Nm adjkerntz
+.Fl i
+.Nm adjkerntz
+.Fl a
.Sh DESCRIPTION
.Nm Adjkerntz
-daemon
fixes kernel time (makes it UTC) using the current wall CMOS clock value,
the current time zone rule and the kernel timezone value. The adjustment is
enabled only if the file
.Pa /etc/wall_cmos_clock
exists, in other cases it is assumed that the machine runs UTC CMOS clock and
.Nm adjkerntz
-does nothing and exits immediately.
+does nothing.
.Pp
-The adjustment is usually needed at boot stage and when a time zone
-change occurs.
-.Nm Adjkerntz
-started in
+The adjustment is needed at boot stage and when a time zone
+change occurs, so
+.Nm adjkerntz
+can be called in two forms:
+.Bl -tag -width 4n
+.It Cm Fl i
+initialization call from
.Pa /etc/rc
(before any daemons are started).
.Nm Adjkerntz
@@ -53,16 +58,21 @@ makes the first adjustment and the initial time zone offset is stored into
kernel variable
for following subsequent
.Nm adjkerntz
-time zone change spying.
-When time zone changes occur,
+calls.
+.It Cm Fl a
+This form is needed, when time zone changes occur.
.Nm Adjkerntz
uses the previously stored
time zone offset and the changed time zone rule to
-produce the new time zone offset, fix RTC clock and store the new
+produce the new time zone offset, fix the RTC clock and store the new
offset into
.Pa adjkerntz
kernel variable
too.
+It is recommended to use this form in root's
+.Xr crontab 5
+every half of a hour from 0am to 4am
+since this times matches most modern time zone changes.
.Pp
.Nm Adjkerntz
clears the kernel timezone structure and makes kernel always run at UTC
@@ -81,7 +91,7 @@ is used.
.Sh FILES
.Bl -tag -width /etc/wall_cmos_clock -compact
.It Pa /etc/localtime
-current zoneinfo file, see
+Current zoneinfo file, see
.Xr /usr/sbin/tzsetup
and
.Xr zic 8 .
@@ -93,6 +103,7 @@ absence indicates UTC CMOS clock.
.Xr tzset 3 ,
.Xr zic 8 ,
.Xr rc 8 ,
+.Xr crontab 5 ,
.Xr sysctl 8 ,
.Xr /usr/sbin/tzsetup
.Sh DIAGNOSTICS
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