Ignore:
Timestamp:
04/03/2014 09:52:09 PM (10 years ago)
Author:
Bruce Dubbs <bdubbs@…>
Branches:
10.0, 10.0-rc1, 10.1, 10.1-rc1, 11.0, 11.0-rc1, 11.0-rc2, 11.0-rc3, 11.1, 11.1-rc1, 11.2, 11.2-rc1, 11.3, 11.3-rc1, 12.0, 12.0-rc1, 12.1, 12.1-rc1, 7.6, 7.7, 7.8, 7.9, 8.0, 8.1, 8.2, 8.3, 8.4, 9.0, 9.1, arm, bdubbs/gcc13, ml-11.0, multilib, renodr/libudev-from-systemd, s6-init, trunk, xry111/arm64, xry111/arm64-12.0, xry111/clfs-ng, xry111/lfs-next, xry111/loongarch, xry111/loongarch-12.0, xry111/loongarch-12.1, xry111/mips64el, xry111/pip3, xry111/rust-wip-20221008, xry111/update-glibc
Children:
9839808
Parents:
008436e
Message:

Added systemd and dbus to the book.
Set up systemd and System V side-by-side with the
ability to reboot to either system.

git-svn-id: ​http://svn.linuxfromscratch.org/LFS/trunk/BOOK@10520 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689

File:
1 edited

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  • chapter07/setclock.xml

    r008436e rcba2d4e  
    66]>
    77
    8 <sect1 id="ch-scripts-setclock">
    9   <?dbhtml filename="setclock.html"?>
     8<sect1 id="ch-scripts-clock">
     9  <?dbhtml filename="clock.html"?>
    1010
    11   <title>Configuring the setclock Script</title>
     11  <title>Configuring the System Clock</title>
    1212
    13   <indexterm zone="ch-scripts-setclock">
    14     <primary sortas="d-setclock">setclock</primary>
    15   <secondary>configuring</secondary></indexterm>
     13  <para>Procedures for setting the system clock differ between systemd and
     14  System V, however the separate procedures do not conflict so both
     15  procedures should be accomplished to allow switching between systems.</para>
    1616
    17   <para>The <command>setclock</command> script reads the time from the hardware
    18   clock, also known as the BIOS or the Complementary Metal Oxide Semiconductor
    19   (CMOS) clock. If the hardware clock is set to UTC, this script will convert the
    20   hardware clock's time to the local time using the
    21   <filename>/etc/localtime</filename> file (which tells the
    22   <command>hwclock</command> program which timezone the user is in). There is no
    23   way to detect whether or not the hardware clock is set to UTC, so this
    24   needs to be configured manually.</para>
     17  <sect2 id="ch-scripts-setclock">
     18    <title>System V Clock Configuration</title>
    2519
    26   <para>The <command>setclock</command> is run via
    27   <application>udev</application> when the kernel detects the hardware
    28   capability upon boot.  It can also be run manually with the stop parameter to
    29   store the system time to the CMOS clock.</para>
     20    <indexterm zone="ch-scripts-setclock">
     21      <primary sortas="d-setclock">setclock</primary>
     22    <secondary>configuring</secondary></indexterm>
    3023
    31   <para>If you cannot remember whether or not the hardware clock is set to UTC,
    32   find out by running the <userinput>hwclock --localtime --show</userinput>
    33   command. This will display what the current time is according to the hardware
    34   clock. If this time matches whatever your watch says, then the hardware clock is
    35   set to local time. If the output from <command>hwclock</command> is not local
    36   time, chances are it is set to UTC time. Verify this by adding or subtracting
    37   the proper amount of hours for the timezone to the time shown by
    38   <command>hwclock</command>. For example, if you are currently in the MST
    39   timezone, which is also known as GMT -0700, add seven hours to the local
    40   time.</para>
     24    <para>The <command>setclock</command> script reads the time from the hardware
     25    clock, also known as the BIOS or the Complementary Metal Oxide Semiconductor
     26    (CMOS) clock. If the hardware clock is set to UTC, this script will convert the
     27    hardware clock's time to the local time using the
     28    <filename>/etc/localtime</filename> file (which tells the
     29    <command>hwclock</command> program which timezone the user is in). There is no
     30    way to detect whether or not the hardware clock is set to UTC, so this
     31    needs to be configured manually.</para>
    4132
    42   <para>Change the value of the <envar>UTC</envar> variable below
    43   to a value of <parameter>0</parameter> (zero) if the hardware clock
    44   is <emphasis>not</emphasis> set to UTC time.</para>
     33    <para>The <command>setclock</command> is run via
     34    <application>udev</application> when the kernel detects the hardware
     35    capability upon boot.  It can also be run manually with the stop parameter to
     36    store the system time to the CMOS clock.</para>
    4537
    46   <para>Create a new file <filename>/etc/sysconfig/clock</filename> by running
    47   the following:</para>
     38    <para>If you cannot remember whether or not the hardware clock is set to UTC,
     39    find out by running the <userinput>hwclock --localtime --show</userinput>
     40    command. This will display what the current time is according to the hardware
     41    clock. If this time matches whatever your watch says, then the hardware clock is
     42    set to local time. If the output from <command>hwclock</command> is not local
     43    time, chances are it is set to UTC time. Verify this by adding or subtracting
     44    the proper amount of hours for the timezone to the time shown by
     45    <command>hwclock</command>. For example, if you are currently in the MST
     46    timezone, which is also known as GMT -0700, add seven hours to the local
     47    time.</para>
     48
     49    <para>Change the value of the <envar>UTC</envar> variable below
     50    to a value of <parameter>0</parameter> (zero) if the hardware clock
     51    is <emphasis>not</emphasis> set to UTC time.</para>
     52
     53    <para>Create a new file <filename>/etc/sysconfig/clock</filename> by running
     54    the following:</para>
    4855
    4956<screen><userinput>cat &gt; /etc/sysconfig/clock &lt;&lt; "EOF"
    … …  
    5966EOF</userinput></screen>
    6067
    61   <para>A good hint explaining how to deal with time on LFS is available
    62   at <ulink url="&hints-root;time.txt"/>. It explains issues such as
    63   time zones, UTC, and the <envar>TZ</envar> environment variable.</para>
     68    <para>A good hint explaining how to deal with time on LFS is available
     69    at <ulink url="&hints-root;time.txt"/>. It explains issues such as
     70    time zones, UTC, and the <envar>TZ</envar> environment variable.</para>
    6471
    65   <note><para>The CLOCKPARAMS and UTC paramaters may be alternatively set
    66   in the <filename>/etc/sysconfig/rc.site</filename> file.</para></note>
     72    <note><para>The CLOCKPARAMS and UTC paramaters may be alternatively set
     73    in the <filename>/etc/sysconfig/rc.site</filename> file.</para></note>
     74
     75  </sect2>
     76
     77  <sect2 id="ch-scripts-systemd-clock">
     78    <title>Systemd Clock Configuration</title>
     79
     80  <indexterm zone="ch-scripts-clock">
     81    <primary sortas="d-clock">clock</primary>
     82  <secondary>configuring</secondary></indexterm>
     83
     84  <para>This section discusses how to configure the
     85  <command>systemd-timedated</command> system service, which configures
     86  system clock and timezone.</para>
     87
     88  <para><command>systemd-timedated</command> reads
     89  <filename>/etc/adjtime</filename>, and depending on the contents of the file,
     90  it sets the clock to either UTC or local time.  Create the
     91  <filename>/etc/adjtime</filename> file with the following contents <emphasis>if your
     92  hardware clock is set to local time</emphasis>:</para>
     93
     94<screen role="nodump"><userinput>cat &gt; /etc/adjtime &lt;&lt; "EOF"
     95<literal>0.0 0 0.0
     960
     97LOCAL</literal>
     98EOF</userinput></screen>
     99
     100    <para>If <filename>/etc/adjtime</filename> isn't present at first boot,
     101    <command>systemd-timedated</command> will assume that hardware clock is
     102    set to UTC and create the file using that setting.</para>
     103
     104    <para>You can also use the <command>timedatectl</command> utility to tell
     105    <command>systemd-timedated</command> if your hardware clock is set to
     106    UTC or local time:</para>
     107
     108<screen role="nodump"><userinput>timedatectl set-local-rtc 1</userinput></screen>
     109
     110    <para><command>timedatectl</command> can also be used to change system time and
     111    time zone.</para>
     112
     113    <para>To change your current system time, issue:</para>
     114
     115<screen role="nodump"><userinput>timedatectl set-time YYYY:MM:DD HH:MM:SS</userinput></screen>
     116
     117    <para>Hardware clock will also be updated accordingly.</para>
     118
     119    <para>To change your current time zone, issue:</para>
     120
     121<screen role="nodump"><userinput>timedatectl set-timezone TIMEZONE</userinput></screen>
     122
     123    <para>You can get list of available time zones by running:</para>
     124
     125<screen role="nodump"><userinput>timedatectl list-timezones</userinput></screen>
     126
     127    <note><para>Please note that <command>timedatectl</command> command can
     128    be used only on a system booted with Systemd.</para></note>
     129
     130  </sect2>
    67131
    68132</sect1>
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