source: BOOK/bootscripts/common/setclock.xml@ e680587

clfs-3.0.0-systemd clfs-3.0.0-sysvinit systemd sysvinit
Last change on this file since e680587 was aa18ac0, checked in by Manuel Canales Esparcia <manuel@…>, 18 years ago

Updated trunk book sources to use DocBook-XML DTD 4.5.

  • Property mode set to 100644
File size: 2.4 KB
Line 
1<?xml version="1.0" encoding="ISO-8859-1"?>
2<!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
3 "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
4 <!ENTITY % general-entities SYSTEM "../../general.ent">
5 %general-entities;
6]>
7
8<sect1 id="ch-scripts-setclock">
9 <?dbhtml filename="setclock.html"?>
10
11 <title>Configuring the setclock Script</title>
12
13 <indexterm zone="ch-scripts-setclock">
14 <primary sortas="d-setclock">setclock</primary>
15 <secondary>configuring</secondary></indexterm>
16
17 <para os="a">The <command>setclock</command> script reads the time from the
18 hardware clock, also known as the BIOS or the Complementary Metal Oxide
19 Semiconductor (CMOS) clock. If the hardware clock is set to UTC, this
20 script will convert the hardware clock's time to the local time using
21 the <filename>/etc/localtime</filename> file (which tells the
22 <command>hwclock</command> program which timezone the user is in). There
23 is no way to detect whether or not the hardware clock is set to UTC, so
24 this needs to be configured manually.</para>
25
26 <para os="b">If you cannot remember whether or not the hardware clock is set
27 to UTC, find out by running the <userinput>hwclock --localtime
28 --show</userinput> command. This will display what the current time is
29 according to the hardware clock. If this time matches whatever your
30 watch says, then the hardware clock is set to local time. If the output
31 from <command>hwclock</command> is not local time, chances are it is set
32 to UTC time. Verify this by adding or subtracting the proper amount of
33 hours for the timezone to the time shown by <command>hwclock</command>.
34 For example, if you are currently in the MST timezone, which is also
35 known as GMT -0700, add seven hours to the local time.</para>
36
37 <para os="c">Change the value of the <envar>UTC</envar> variable below
38 to a value of <option>0</option> (zero) if the hardware clock
39 is <emphasis>not</emphasis> set to UTC time.</para>
40
41 <para os="d">Create a new file <filename>/etc/sysconfig/clock</filename> by running
42 the following:</para>
43
44<screen><userinput>cat &gt; /etc/sysconfig/clock &lt;&lt; "EOF"
45<literal># Begin /etc/sysconfig/clock
46
47UTC=1
48
49# End /etc/sysconfig/clock</literal>
50EOF</userinput></screen>
51
52 <para os="e">A good hint explaining how to deal with time on CLFS is available
53 at <ulink url="&hints-root;time.txt"/>. It explains issues such as
54 time zones, UTC, and the <envar>TZ</envar> environment variable.</para>
55
56</sect1>
Note: See TracBrowser for help on using the repository browser.