diff options
Diffstat (limited to 'chapter07')
| -rw-r--r-- | chapter07/bootscripts.xml | 5 | ||||
| -rw-r--r-- | chapter07/chapter07.xml | 14 | ||||
| -rw-r--r-- | chapter07/introduction.xml | 23 | ||||
| -rw-r--r-- | chapter07/network.xml | 219 | ||||
| -rw-r--r-- | chapter07/symlinks.xml | 148 | ||||
| -rw-r--r-- | chapter07/sysd-custom.xml | 139 | ||||
| -rw-r--r-- | chapter07/udev.xml | 96 | ||||
| -rw-r--r-- | chapter07/usage.xml | 462 |
8 files changed, 893 insertions, 213 deletions
diff --git a/chapter07/bootscripts.xml b/chapter07/bootscripts.xml index 64e244d79..51a5b8f9c 100644 --- a/chapter07/bootscripts.xml +++ b/chapter07/bootscripts.xml @@ -24,8 +24,9 @@ <title/> <para>The LFS-Bootscripts package contains a set of scripts to start/stop - the LFS system at bootup/shutdown. The networking systemd unit file is - also installed.</para> + the LFS system at bootup/shutdown. A networking systemd unit file is + also installed. The configuration files and procedures needed to + customize the boot process are described in the following sections.</para> <segmentedlist> <segtitle>&buildtime;</segtitle> diff --git a/chapter07/chapter07.xml b/chapter07/chapter07.xml index ae298f0b0..695f471c5 100644 --- a/chapter07/chapter07.xml +++ b/chapter07/chapter07.xml @@ -13,17 +13,17 @@ <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="introduction.xml"/> <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="bootscripts.xml"/> - <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="network.xml"/> - <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="hosts.xml"/> <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="udev.xml"/> <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="symlinks.xml"/> + <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="network.xml"/> +<!-- <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="hosts.xml"/>--> <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="usage.xml"/> <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="sysd-custom.xml"/> - <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="hostname.xml"/> - <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="setclock.xml"/> - <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="console.xml"/> - <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="sysklogd.xml"/> - <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="site.xml"/> +<!-- <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="hostname.xml"/>--> +<!-- <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="setclock.xml"/>--> +<!-- <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="console.xml"/>--> +<!-- <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="sysklogd.xml"/>--> +<!-- <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="site.xml"/>--> <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="profile.xml"/> <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="inputrc.xml"/> diff --git a/chapter07/introduction.xml b/chapter07/introduction.xml index 27c5dbba4..243bad3b9 100644 --- a/chapter07/introduction.xml +++ b/chapter07/introduction.xml @@ -39,15 +39,15 @@ <filename>/etc/inittab</filename> file and is organized into run levels that can be run by the user:</para> - <itemizedlist> - <listitem><para>0 — halt</para></listitem> - <listitem><para>1 — Single user mode</para></listitem> - <listitem><para>2 — Multiuser, without networking</para></listitem> - <listitem><para>3 — Full multiuser mode</para></listitem> - <listitem><para>4 — User definable</para></listitem> - <listitem><para>5 — Full multiuser mode with display manager</para></listitem> - <listitem><para>6 — reboot</para></listitem> - </itemizedlist> +<literallayout> +0 — halt +1 — Single user mode +2 — Multiuser, without networking +3 — Full multiuser mode +4 — User definable +5 — Full multiuser mode with display manager +6 — reboot +</literallayout> <para>The usual default run level is 3 or 5.</para> @@ -207,6 +207,11 @@ EOF chmod 0744 /usr/sbin/set-sysv</userinput></screen> + <note><para>The comment about the correct command to reboot in the + above scripts is correct. The reboot command for the current boot + system must be used after the script changes the default reboot command. + </para></note> + <para>Now set the desired boot system. The default is System V:</para> <screen><userinput remap="install">/usr/sbin/set-sysv</userinput></screen> diff --git a/chapter07/network.xml b/chapter07/network.xml index 4134bb40c..97ecf894e 100644 --- a/chapter07/network.xml +++ b/chapter07/network.xml @@ -24,106 +24,11 @@ class="directory">/etc/rc.d/rc*.d</filename>) after the bootscripts are installed in <xref linkend="ch-scripts-bootscripts"/>.</para> - <sect2 id='stable-net-names'> - <title>Creating stable names for network interfaces</title> - - <para>If there is only one network interface in the system to be - configured, this section is optional, although it will never be wrong to do - it. In many cases (e.g. a laptop with a wireless and a wired interface), - accomplishing the configuration in this section is necessary.</para> - - <para>With Udev and modular network drivers, the network interface numbering - is not persistent across reboots by default, because the drivers are loaded - in parallel and, thus, in random order. For example, on a computer having - two network cards made by Intel and Realtek, the network card manufactured - by Intel may become <filename class="devicefile">eth0</filename> and the - Realtek card becomes <filename class="devicefile">eth1</filename>. In some - cases, after a reboot the cards get renumbered the other way around. To - avoid this, Udev comes with a script and some rules to assign stable names - to network cards based on their MAC address.</para> - - <para>If using the traditional network interface names such as eth0 is desired, - generate a custom Udev rule:</para> - -<screen><userinput>bash /lib/udev/init-net-rules.sh</userinput></screen> - - <para> Now, inspect the - <filename>/etc/udev/rules.d/70-persistent-net.rules</filename> file, to - find out which name was assigned to which network device:</para> - -<screen role="nodump"><userinput>cat /etc/udev/rules.d/70-persistent-net.rules</userinput></screen> - - <note><para>In some cases such as when MAC addresess have been assigned to - a network card manually or in a virtual environment such as Xen, - the network rules file may not have been generated because addresses - are not consistently assigned. In these cases, just continue to - the next section.</para></note> - - <para>The file begins with a comment block followed by two lines for each - NIC. The first line for each NIC is a commented description showing its - hardware IDs (e.g. its PCI vendor and device IDs, if it's a PCI card), - along with its driver in parentheses, if the driver can be found. Neither - the hardware ID nor the driver is used to determine which name to give an - interface; this information is only for reference. The second line is the - Udev rule that matches this NIC and actually assigns it a name.</para> - - <para>All Udev rules are made up of several keys, separated by commas and - optional whitespace. This rule's keys and an explanation of each of them - are as follows:</para> - - <itemizedlist> - <listitem> - <para><literal>SUBSYSTEM=="net"</literal> - This tells Udev to ignore - devices that are not network cards.</para> - </listitem> - <listitem> - <para><literal>ACTION=="add"</literal> - This tells Udev to ignore this - rule for a uevent that isn't an add ("remove" and "change" uevents also - happen, but don't need to rename network interfaces).</para> - </listitem> - <listitem> - <para><literal>DRIVERS=="?*"</literal> - This exists so that Udev will - ignore VLAN or bridge sub-interfaces (because these sub-interfaces do - not have drivers). These sub-interfaces are skipped because the name - that would be assigned would collide with their parent devices.</para> - </listitem> - <listitem> - <para><literal>ATTR{address}</literal> - The value of this key is the - NIC's MAC address.</para> - </listitem> - <listitem> - <para><literal>ATTR{type}=="1"</literal> - This ensures the rule only - matches the primary interface in the case of certain wireless drivers, - which create multiple virtual interfaces. The secondary interfaces are - skipped for the same reason that VLAN and bridge sub-interfaces are - skipped: there would be a name collision otherwise.</para> - </listitem> - <listitem> - <para><literal>KERNEL=="eth*"</literal> - This key was added to the - Udev rule generator to handle machines that have multiple network - interfaces, all with the same MAC address (the PS3 is one such - machine). If the independent interfaces have different basenames, - this key will allow Udev to tell them apart. This is generally not - necessary for most Linux From Scratch users, but does not hurt.</para> - </listitem> - <listitem> - <para><literal>NAME</literal> - The value of this key is the name that - Udev will assign to this interface.</para> - </listitem> - </itemizedlist> - - <para>The value of <literal>NAME</literal> is the important part. Make sure - you know which name has been assigned to each of your network cards before - proceeding, and be sure to use that <literal>NAME</literal> value when - creating your configuration files below.</para> - - </sect2> - <sect2> <title>Creating Network Interface Configuration Files</title> <para>Which interfaces are brought up and down by the network script - depends on the files in <filename + usually depends on the files in <filename class="directory">/etc/sysconfig/</filename>. This directory should contain a file for each interface to be configured, such as <filename>ifconfig.xyz</filename>, where <quote>xyz</quote> is required to @@ -216,12 +121,38 @@ EOF</userinput></screen> <para>Replace eth0 with the correct network interface card name as described on the beginning of this page.</para> + <note><para>These procedures require the configuartion files as specified + in the previous section.</para></note> + <note><para>The network card can also be started or stopped with the traditional <command>ifup <device></command> or <command>ifdown <device></command> commands.</para></note> </sect2> + <sect2 id="systemd2-net-enable"> + <title>Configuring the Network Interface Card for systemd-networkd</title> + + <para>An alternative way to configure a NIC when booting with with + systemd is to create a configuration file recognized by the + systemd-networkd daemon. To configure the device create a file similar + to this:</para> + +<screen role="nodump"><userinput>cat > /etc/systemd/network/10-static-eth0.network << "EOF" +[Match] +Name=eth0 + +[Network] +Address=192.168.0.2/24 +Gateway=192.168.0.1 +EOF</userinput></screen> + + <para>You can use multiple .network files if desired. You can also specify + DHCP=yes instead of the Address and Gateway settings. See the man page for + systemd.network for more details,</para> + + </sect2> + <sect2 id="resolv.conf"> <title>Creating the /etc/resolv.conf File</title> @@ -262,4 +193,100 @@ EOF</userinput></screen> </sect2> + <sect2 id="ch-scripts-hostname"> + <title>Configuring the system hostname</title> + + <indexterm zone="ch-scripts-hostname"> + <primary sortas="d-hostname">hostname</primary> + <secondary>configuring</secondary> + </indexterm> + + <para>During the boot process, both Systemd and System V use the same file + for establishing the system's hostname. This needs to be configured by + creating <filename>/etc/hostname</filename>.</para> + + <para>Create the <filename>/etc/hostname</filename> file and enter a + hostname by running:</para> + +<screen><userinput>echo "<replaceable><lfs></replaceable>" > /etc/hostname</userinput></screen> + + <para><replaceable><lfs></replaceable> needs to be replaced with the + name given to the computer. Do not enter the Fully Qualified Domain Name + (FQDN) here. That information is put in the + <filename>/etc/hosts</filename> file.</para> + + </sect2> + + <sect2 id="ch-scripts-hosts"> + <title>Customizing the /etc/hosts File</title> + + <indexterm zone="ch-scripts-hosts"> + <primary sortas="e-/etc/hosts">/etc/hosts</primary> + </indexterm> + + <indexterm zone="ch-scripts-hosts"> + <primary sortas="d-localnet">localnet</primary> + <secondary>/etc/hosts</secondary> + </indexterm> + + <indexterm zone="ch-scripts-hosts"> + <primary sortas="d-network">network</primary> + <secondary>/etc/hosts</secondary> + </indexterm> + + <para>Decide on the IP address, fully-qualified domain name (FQDN), and + possible aliases for use in the <filename>/etc/hosts</filename> file. The + syntax is:</para> + +<screen><literal>IP_address myhost.example.org aliases</literal></screen> + + <para>Unless the computer is to be visible to the Internet (i.e., there is + a registered domain and a valid block of assigned IP addresses—most + users do not have this), make sure that the IP address is in the private + network IP address range. Valid ranges are:</para> + +<screen><literal>Private Network Address Range Normal Prefix +10.0.0.1 - 10.255.255.254 8 +172.x.0.1 - 172.x.255.254 16 +192.168.y.1 - 192.168.y.254 24</literal></screen> + + <para>x can be any number in the range 16-31. y can be any number in the + range 0-255.</para> + + <para>A valid private IP address could be 192.168.1.1. A valid FQDN for + this IP could be lfs.example.org.</para> + + <para>Even if not using a network card, a valid FQDN is still required. + This is necessary for certain programs to operate correctly.</para> + + <para>Create the <filename>/etc/hosts</filename> file by running:</para> + +<screen><userinput>cat > /etc/hosts << "EOF" +<literal># Begin /etc/hosts (network card version) + +127.0.0.1 localhost +<replaceable><192.168.1.1></replaceable> <replaceable><HOSTNAME.example.org></replaceable> <replaceable>[alias1] [alias2 ...]</replaceable> + +# End /etc/hosts (network card version)</literal> +EOF</userinput></screen> + + <para>The <replaceable><192.168.1.1></replaceable> and + <replaceable><HOSTNAME.example.org></replaceable> values need to be + changed for specific uses or requirements (if assigned an IP address by a + network/system administrator and the machine will be connected to an + existing network). The optional alias name(s) can be omitted.</para> + + <para>If a network card is not going to be configured, create the + <filename>/etc/hosts</filename> file by running:</para> + +<screen role="nodump"><userinput>cat > /etc/hosts << "EOF" +<literal># Begin /etc/hosts (no network card version) + +127.0.0.1 <replaceable><HOSTNAME.example.org></replaceable> <replaceable><HOSTNAME></replaceable> localhost + +# End /etc/hosts (no network card version)</literal> +EOF</userinput></screen> + + </sect2> + </sect1> diff --git a/chapter07/symlinks.xml b/chapter07/symlinks.xml index bba84e369..1d4467a15 100644 --- a/chapter07/symlinks.xml +++ b/chapter07/symlinks.xml @@ -8,7 +8,151 @@ <sect1 id="ch-scripts-symlinks"> <?dbhtml filename="symlinks.html"?> - <title>Creating Custom Symlinks to Devices</title> + <title>Managing Devices</title> + + <sect2> + + <title>Network Devices</title> + + <para>Udev, by default, names network devices according to Firmware/BIOS + data or physical characteristics like the bus, slot, or MAC address. The + purpose of this naming convention is to ensure that network devices are + named consistently and not based on the time the network card was + discovered. For example, on a computer having two network cards made by + Intel and Realtek, the network card manufactured by Intel may become eth0 + and the Realtek card becomes eth1. In some cases, after a reboot the cards + get renumbered the other way around.</para> + + <para>In the new naming scheme, typical network device names would then + be something like enp5s0 or wlp3s0. If this naming convention is not + desired, the traditional naming scheme or a custom scheme can be + implemented.</para> + + <sect3> + <title>Disabling Persistent Naming on the Kernel Command Line</title> + + <para>The traditional naming scheme using eth0, eth1, etc can be + restored by adding <userinput>net.ifnames=0</userinput> on the + kernel command line. This is most appropriate for those systems + that have only one ethernet device of the same type. Laptops + often have multiple ethernet connections that are named eth0 and + wlan0 and are also candidates for this method. The command line + is passed in the GRUB configuration file. + See <xref linkend="grub-cfg"/>.</para> + </sect3> + + <sect3> + <title>Creating Custom Udev Rules</title> + + <para>The naming scheme can be customized by creating custom Udev + rules. A script has been included that generates the initial rules. + Generate these rules by running:</para> + +<screen role="nodump"><userinput>bash /lib/udev/init-net-rules.sh</userinput></screen> + + <para> Now, inspect th + <filename>/etc/udev/rules.d/70-persistent-net.rules</filename> file, to + find out which name was assigned to which network device:</para> + +<screen role="nodump"><userinput>cat /etc/udev/rules.d/70-persistent-net.rules</userinput></screen> + + <note><para>In some cases such as when MAC addresess have been assigned to + a network card manually or in a virtual environment such as Qemu or Xen, + the network rules file may not have been generated because addresses + are not consistently assigned. In these cases, this method cannot + be used.</para></note> + + <para>The file begins with a comment block followed by two lines for each + NIC. The first line for each NIC is a commented description showing its + hardware IDs (e.g. its PCI vendor and device IDs, if it's a PCI card), + along with its driver in parentheses, if the driver can be found. Neither + the hardware ID nor the driver is used to determine which name to give an + interface; this information is only for reference. The second line is the + Udev rule that matches this NIC and actually assigns it a name.</para> + + <para>All Udev rules are made up of several keys, separated by commas and + optional whitespace. This rule's keys and an explanation of each of them + are as follows:</para> + + <itemizedlist> + <listitem> + <para><literal>SUBSYSTEM=="net"</literal> - This tells Udev to ignore + devices that are not network cards.</para> + </listitem> + <listitem> + <para><literal>ACTION=="add"</literal> - This tells Udev to ignore this + rule for a uevent that isn't an add ("remove" and "change" uevents also + happen, but don't need to rename network interfaces).</para> + </listitem> + <listitem> + <para><literal>DRIVERS=="?*"</literal> - This exists so that Udev will + ignore VLAN or bridge sub-interfaces (because these sub-interfaces do + not have drivers). These sub-interfaces are skipped because the name + that would be assigned would collide with their parent devices.</para> + </listitem> + <listitem> + <para><literal>ATTR{address}</literal> - The value of this key is the + NIC's MAC address.</para> + </listitem> + <listitem> + <para><literal>ATTR{type}=="1"</literal> - This ensures the rule only + matches the primary interface in the case of certain wireless drivers, + which create multiple virtual interfaces. The secondary interfaces are + skipped for the same reason that VLAN and bridge sub-interfaces are + skipped: there would be a name collision otherwise.</para> + </listitem> + <listitem> + <para><literal>NAME</literal> - The value of this key is the name that + Udev will assign to this interface.</para> + </listitem> + </itemizedlist> + + <para>The value of <literal>NAME</literal> is the important part. Make sure + you know which name has been assigned to each of your network cards before + proceeding, and be sure to use that <literal>NAME</literal> value when + creating your configuration files below.</para> + + </sect3> + + <sect3> + <title>Custom Naming in Systemd</title> + + <para>Network interface names can also be customized with a set of + files spcific to systemd. A file with a name such as 10-eth0.link + in the /etc/systemd/network directory can set an interface name. All + files in the directory will be applied in lexical order. Files + in the /lib/systemd/network directory with the same name as those + in /etc/systemd/network will be overridden. See the man page + for systemd.link for a full explanation.</para> + + <para>An example file looks like:</para> + +<screen role="nodump">[Match] +MACAddress=12:34:56:78:9a:bc +Driver=brcmsmac +Path=pci-0000:02:00.0-* +Type=wlan +Virtualization=no +Host=my-laptop +Architecture=x86-64 + +[Link] +Name=wireless0 +MTUBytes=1450 +BitsPerSecond=10M +WakeOnLan=magic +MACAddress=cb:a9:87:65:43:21</screen> + + <para>The [Match] section specifies when to apply the rule. In + the example above, the entries can be shortened to the minimum + needed to uniquely identify the network device. Similarly, + the [Link] section only needs to specify the changes from the + default that are desired. In many cases, the only thing needed is + the Name entry.</para> + + </sect3> + + </sect2> <sect2> @@ -108,7 +252,7 @@ <filename>/dev/video1</filename> refers to the tuner, and sometimes after a reboot the order changes to the opposite one. For all classes of hardware except sound cards and network cards, this is - fixable by creating udev rules for custom persistent symlinks. + fixable by creating Udev rules for custom persistent symlinks. The case of network cards is covered separately in <xref linkend="ch-scripts-network"/>, and sound card configuration can be found in <ulink url="&blfs-root;view/svn/postlfs/devices.html">BLFS</ulink>.</para> diff --git a/chapter07/sysd-custom.xml b/chapter07/sysd-custom.xml index 7f3d4864b..e5872ece9 100644 --- a/chapter07/sysd-custom.xml +++ b/chapter07/sysd-custom.xml @@ -8,7 +8,7 @@ <sect1 id="ch-scripts-sysd-custom"> <?dbhtml filename="sysd-custom.html"?> - <title>Systemd Customization</title> + <title>Systemd Usage and Confiuration</title> <indexterm zone="ch-scripts-sysd-custom"> <primary sortas="e-Systemd">Systemd Customization</primary> @@ -98,6 +98,143 @@ EOF</userinput></screen> </sect2> + <sect2 id="ch-scripts-systemd-console"> + <title>Setting Console Fonts and Keyboard</title> + + <indexterm zone="ch-scripts-systemd-console"> + <primary sortas="d-console">systemd console</primary> + <secondary>configuring</secondary> + </indexterm> + + <para>This section discusses how to configure the + <command>systemd-vconsole-setup</command> system service, which configures + the virtual console font and console keymap.</para> + + <para>The <command>systemd-vconsole-setup</command> service reads the + <filename>/etc/vconsole.conf</filename> file for configuration + information. Decide which keymap and screen font will be used. Various + language-specific HOWTOs can also help with this, see <ulink + url="http://www.tldp.org/HOWTO/HOWTO-INDEX/other-lang.html"/>. + Examine <command>localectl list-keymaps</command> output for a list of + valid console keymaps. Look in + <filename class="directory">/usr/share/consolefonts</filename> + directory for valid screen fonts.</para> + + <para>The <filename>/etc/vconsole.conf</filename> file should contain lines + of the form: VARIABLE="value". The following variables are recognized:</para> + + <variablelist> + + <varlistentry> + <term>KEYMAP</term> + <listitem> + <para>This variable specifies the key mapping table for the keyboard. If + unset, it defaults to <literal>us</literal>.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term>KEYMAP_TOGGLE</term> + <listitem> + <para>This variable can be used to configure a second toggle keymap and + is unset by default.</para> + </listitem> + </varlistentry> + <varlistentry> + <term>FONT</term> + <listitem> + <para>This variable specifies the font used by the virtual + console.</para> + </listitem> + </varlistentry> + <varlistentry> + <term>FONT_MAP</term> + <listitem> + <para>This variable specifies the console map to be used.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term>FONT_UNIMAP</term> + <listitem> + <para>This variable specifies the unicode font map.</para> + </listitem> + </varlistentry> + + </variablelist> + + <para>An example for a German keyboard and console is given below:</para> + +<screen role="nodump"><userinput>cat > /etc/vconsole.conf << "EOF" +<literal>KEYMAP=de-latin1 +FONT=Lat2-Terminus16</literal> +EOF</userinput></screen> + + <para>You can change KEYMAP value at runtime by using the + <command>localectl</command> utility:</para> + +<screen role="nodump"><userinput>localectl set-keymap MAP</userinput></screen> + + <note><para>Please note that <command>localectl</command> command can + be used only on a system booted with Systemd.</para></note> + + </sect2> + + <sect2> + <title>Clock Configuration</title> + + <indexterm zone="ch-scripts-clock"> + <primary sortas="d-clock">clock</primary> + <secondary>configuring</secondary></indexterm> + + <para>This section discusses how to configure the + <command>systemd-timedated</command> system service, which configures + system clock and timezone.</para> + + <para><command>systemd-timedated</command> reads + <filename>/etc/adjtime</filename>, and depending on the contents of the file, + it sets the clock to either UTC or local time. Create the + <filename>/etc/adjtime</filename> file with the following contents <emphasis>if your + hardware clock is set to local time</emphasis>:</para> + +<screen role="nodump"><userinput>cat > /etc/adjtime << "EOF" +<literal>0.0 0 0.0 +0 +LOCAL</literal> +EOF</userinput></screen> + + <para>If <filename>/etc/adjtime</filename> isn't present at first boot, + <command>systemd-timedated</command> will assume that hardware clock is + set to UTC and create the file using that setting.</para> + + <para>You can also use the <command>timedatectl</command> utility to tell + <command>systemd-timedated</command> if your hardware clock is set to + UTC or local time:</para> + +<screen role="nodump"><userinput>timedatectl set-local-rtc 1</userinput></screen> + + <para><command>timedatectl</command> can also be used to change system time and + time zone.</para> + + <para>To change your current system time, issue:</para> + +<screen role="nodump"><userinput>timedatectl set-time YYYY:MM:DD HH:MM:SS</userinput></screen> + + <para>Hardware clock will also be updated accordingly.</para> + + <para>To change your current time zone, issue:</para> + +<screen role="nodump"><userinput>timedatectl set-timezone TIMEZONE</userinput></screen> + + <para>You can get list of available time zones by running:</para> + +<screen role="nodump"><userinput>timedatectl list-timezones</userinput></screen> + + <note><para>The <command>timedatectl</command> command can + be used only on a system booted with Systemd.</para></note> + + </sect2> + <sect2> <title>Debugging the Boot Sequence</title> diff --git a/chapter07/udev.xml b/chapter07/udev.xml index 7e11388d8..f8a73d8e9 100644 --- a/chapter07/udev.xml +++ b/chapter07/udev.xml @@ -8,7 +8,7 @@ <sect1 id="ch-scripts-udev"> <?dbhtml filename="udev.html"?> - <title>Device and Module Handling on an LFS System</title> + <title>Overview of Device and Module Handling</title> <indexterm zone="ch-scripts-udev"> <primary sortas="a-Udev">Udev</primary> @@ -16,15 +16,15 @@ </indexterm> <para>In <xref linkend="chapter-building-system"/>, we installed the Udev - package. Before we go into the details regarding how this works, - a brief history of previous methods of handling devices is in + package as a part of systemd. Before we go into the details regarding how + this works, a brief history of previous methods of handling devices is in order.</para> - <para>Linux systems in general traditionally use a static device creation - method, whereby a great many device nodes are created under <filename + <para>Linux systems in general traditionally used a static device creation + method, whereby a great many device nodes were created under <filename class="directory">/dev</filename> (sometimes literally thousands of nodes), - regardless of whether the corresponding hardware devices actually exist. This - is typically done via a <command>MAKEDEV</command> script, which contains a + regardless of whether the corresponding hardware devices actually existed. This + was typically done via a <command>MAKEDEV</command> script, which contains a number of calls to the <command>mknod</command> program with the relevant major and minor device numbers for every possible device that might exist in the world.</para> @@ -53,8 +53,8 @@ device names are allowed to be configurable, then the device naming policy should be up to a system administrator, not imposed on them by any particular developer(s). The <systemitem - class="filesystem">devfs</systemitem> file system also suffers from race - conditions that are inherent in its design and cannot be fixed without a + class="filesystem">devfs</systemitem> file system also suffered from race + conditions that were inherent in its design and could not be fixed without a substantial revision to the kernel. It was marked as deprecated for a long period – due to a lack of maintenance – and was finally removed from the kernel in June, 2006.</para> @@ -64,7 +64,7 @@ <systemitem class="filesystem">sysfs</systemitem> came to be. The job of <systemitem class="filesystem">sysfs</systemitem> is to export a view of the system's hardware configuration to userspace processes. With this - userspace-visible representation, the possibility of seeing a userspace + userspace-visible representation, the possibility of developing a userspace replacement for <systemitem class="filesystem">devfs</systemitem> became much more realistic.</para> @@ -97,7 +97,7 @@ <para>Device files are created by the kernel by the <systemitem class="filesystem">devtmpfs</systemitem> filesystem. Any driver that - wishes to register a device node will go through <systemitem + wishes to register a device node will go through the <systemitem class="filesystem">devtmpfs</systemitem> (via the driver core) to do it. When a <systemitem class="filesystem">devtmpfs</systemitem> instance is mounted on <filename class="directory">/dev</filename>, the device node @@ -113,53 +113,12 @@ change its permissions, owner, or group, or modify the internal <command>udevd</command> database entry (name) for that object.</para> - <para>The rules in these three directories are numbered in a similar - fashion to the LFS-Bootscripts package and all three directories are - merged together. If <command>udevd</command> can't find a rule for the - device it is creating, it will leave the permissions and ownership at - whatever <systemitem class="filesystem">devtmpfs</systemitem> used - initially.</para> </sect3> - - <sect3> - <title>Udev Bootscripts</title> - - <para>The first LFS bootscript, - <filename>/etc/init.d/mountvirtfs</filename> will copy any devices - located in <filename class="directory">/lib/udev/devices</filename> to - <filename class="directory">/dev</filename>. This is necessary because - some devices, directories, and symlinks are needed before the dynamic - device handling processes are available during the early stages of - booting a system, or are required by <command>udevd</command> itself. - Creating static device nodes in <filename - class="directory">/lib/udev/devices</filename> also provides an easy - workaround for devices that are not supported by the dynamic device - handling infrastructure.</para> - - <para>The <filename>/etc/rc.d/init.d/udev</filename> initscript starts - <command>udevd</command>, triggers any "coldplug" devices that have - already been created by the kernel and waits for any rules to complete. - The script also unsets the uevent handler from the default of - <filename>/sbin/hotplug </filename>. This is done because the kernel no - longer needs to call out to an external binary. Instead - <command>udevd</command> will listen on a netlink socket for uevents that - the kernel raises.</para> - - <para>The <command>/etc/rc.d/init.d/udev_retry</command> initscript takes - care of re-triggering events for subsystems whose rules may rely on - filesystems that are not mounted until the <command>mountfs</command> - script is run (in particular, <filename class="directory">/usr</filename> - and <filename class="directory">/var</filename> may cause this). This - script runs after the <command>mountfs</command> script, so those rules - (if re-triggered) should succeed the second time around. It is - configured from the <filename>/etc/sysconfig/udev_retry</filename> file; - any words in this file other than comments are considered subsystem names - to trigger at retry time. To find the subsystem of a device, use - <command>udevadm info --attribute-walk <device></command> where - <device> is an absolute path in /dev or /sys such as /dev/sr0 or - /sys/class/rtc.</para> - - </sect3> - + <para>The rules in these three directories are numbered and all three + directories are merged together. If <command>udevd</command> can't find a + rule for the device it is creating, it will leave the permissions and + ownership at whatever <systemitem + class="filesystem">devtmpfs</systemitem> used initially.</para> </sect3> + <sect3> <title>Module Loading</title> @@ -314,27 +273,6 @@ </sect3> <sect3> - <title>Udev does not create a device</title> - - <para>Further text assumes that the driver is built statically into the - kernel or already loaded as a module, and that you have already checked - that Udev doesn't create a misnamed device.</para> - - <para>Udev has no information needed to create a device node if a kernel - driver does not export its data to <systemitem - class="filesystem">sysfs</systemitem>. - This is most common with third party drivers from outside the kernel - tree. Create a static device node in - <filename>/lib/udev/devices</filename> with the appropriate major/minor - numbers (see the file <filename>devices.txt</filename> inside the kernel - documentation or the documentation provided by the third party driver - vendor). The static device node will be copied to - <filename class="directory">/dev</filename> by the - <command>udev</command> bootscript.</para> - - </sect3> - - <sect3> <title>Device naming order changes randomly after rebooting</title> <para>This is due to the fact that Udev, by design, handles uevents and diff --git a/chapter07/usage.xml b/chapter07/usage.xml index 3250cd328..3eb323a6e 100644 --- a/chapter07/usage.xml +++ b/chapter07/usage.xml @@ -2,32 +2,36 @@ <!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [ <!ENTITY % general-entities SYSTEM "../general.ent"> + <!ENTITY site SYSTEM "../appendices/rc.site.script"> %general-entities; ]> <sect1 id="ch-scripts-usage"> <?dbhtml filename="usage.html"?> - <title>How Do the System V Bootscripts Work?</title> + <title>System V Bootscript Usage and Configuration</title> <indexterm zone="ch-scripts-usage"> <primary sortas="a-Bootscripts">Bootscripts</primary> <secondary>usage</secondary> </indexterm> - <para>Linux uses a special booting facility named SysVinit that is based on a - concept of <emphasis>run-levels</emphasis>. It can be quite different from one - system to another, so it cannot be assumed that because things worked in one - particular Linux distribution, they should work the same in LFS too. LFS has its - own way of doing things, but it respects generally accepted standards.</para> - - <para>SysVinit (which will be referred to as <quote>init</quote> from now on) - works using a run-levels scheme. There are seven (numbered 0 to 6) run-levels - (actually, there are more run-levels, but they are for special cases and are - generally not used. See <filename>init(8)</filename> for more details), and - each one of those corresponds to the actions the computer is supposed to - perform when it starts up. The default run-level is 3. Here are the - descriptions of the different run-levels as they are implemented:</para> + <sect2> + <title>How Do the System V Bootscripts Work?</title> + + <para>Linux uses a special booting facility named SysVinit that is based on a + concept of <emphasis>run-levels</emphasis>. It can be quite different from one + system to another, so it cannot be assumed that because things worked in one + particular Linux distribution, they should work the same in LFS too. LFS has its + own way of doing things, but it respects generally accepted standards.</para> + + <para>SysVinit (which will be referred to as <quote>init</quote> from now on) + works using a run-levels scheme. There are seven (numbered 0 to 6) run-levels + (actually, there are more run-levels, but they are for special cases and are + generally not used. See <filename>init(8)</filename> for more details), and + each one of those corresponds to the actions the computer is supposed to + perform when it starts up. The default run-level is 3. Here are the + descriptions of the different run-levels as they are implemented:</para> <literallayout>0: halt the computer 1: single-user mode @@ -37,6 +41,8 @@ 5: same as 4, it is usually used for GUI login (like X's <command>xdm</command> or KDE's <command>kdm</command>) 6: reboot the computer</literallayout> + </sect2> + <sect2 id="conf-sysvinit" role="configuration"> <title>Configuring Sysvinit</title> @@ -106,9 +112,7 @@ EOF</userinput></screen> persistent across boots, however it is appended to the more permanent file <filename>/var/log/boot.log</filename> at the end of the boot process.</para> - </sect2> - - <sect2 id="init-levels" > + <sect3 id="init-levels" > <title>Changing Run Levels</title> <para>Changing run-levels is done with <command>init @@ -200,6 +204,430 @@ EOF</userinput></screen> it is your own LFS system). The files given here are an example of how it can be done.</para> + </sect3> + </sect2> + + <sect2 id="ch-scripts-clock"> + <title>Configuring the System Clock</title> + + <sect3 id="ch-scripts-setclock"> + <title>System V Clock Configuration</title> + + <indexterm zone="ch-scripts-setclock"> + <primary sortas="d-setclock">setclock</primary> + <secondary>configuring</secondary></indexterm> + + <para>The <command>setclock</command> script reads the time from the hardware + clock, also known as the BIOS or the Complementary Metal Oxide Semiconductor + (CMOS) clock. If the hardware clock is set to UTC, this script will convert the + hardware clock's time to the local time using the + <filename>/etc/localtime</filename> file (which tells the + <command>hwclock</command> program which timezone the user is in). There is no + way to detect whether or not the hardware clock is set to UTC, so this + needs to be configured manually.</para> + + <para>The <command>setclock</command> is run via + <application>udev</application> when the kernel detects the hardware + capability upon boot. It can also be run manually with the stop parameter to + store the system time to the CMOS clock.</para> + + <para>If you cannot remember whether or not the hardware clock is set to UTC, + find out by running the <userinput>hwclock --localtime --show</userinput> + command. This will display what the current time is according to the hardware + clock. If this time matches whatever your watch says, then the hardware clock is + set to local time. If the output from <command>hwclock</command> is not local + time, chances are it is set to UTC time. Verify this by adding or subtracting + the proper amount of hours for the timezone to the time shown by + <command>hwclock</command>. For example, if you are currently in the MST + timezone, which is also known as GMT -0700, add seven hours to the local + time.</para> + + <para>Change the value of the <envar>UTC</envar> variable below + to a value of <parameter>0</parameter> (zero) if the hardware clock + is <emphasis>not</emphasis> set to UTC time.</para> + + <para>Create a new file <filename>/etc/sysconfig/clock</filename> by running + the following:</para> + +<screen><userinput>cat > /etc/sysconfig/clock << "EOF" +<literal># Begin /etc/sysconfig/clock + +UTC=1 + +# Set this to any options you might need to give to hwclock, +# such as machine hardware clock type for Alphas. +CLOCKPARAMS= + +# End /etc/sysconfig/clock</literal> +EOF</userinput></screen> + + <para>A good hint explaining how to deal with time on LFS is available + at <ulink url="&hints-root;time.txt"/>. It explains issues such as + time zones, UTC, and the <envar>TZ</envar> environment variable.</para> + + <note><para>The CLOCKPARAMS and UTC paramaters may be alternatively set + in the <filename>/etc/sysconfig/rc.site</filename> file.</para></note> + + </sect3> </sect2> + <sect2 id="ch-scripts-console"> + <?dbhtml filename="console.html"?> + + <title>Configuring the Linux Console</title> + + <indexterm zone="ch-scripts-console"> + <primary sortas="d-console">console</primary> + <secondary>configuring</secondary> + </indexterm> + + <para>This section discusses how to configure the <command>console</command> + bootscript that sets up the keyboard map, console font and console kernel log + level. If non-ASCII characters (e.g., the copyright sign, the British pound + sign and Euro symbol) will not be used and the keyboard is a U.S. one, much + of this section can be skipped. Without the configuration file, (or + equivalent settings in <filename>rc.site</filename>), the + <command>console</command> bootscript will do nothing.</para> + + <para>The <command>console</command> script reads the + <filename>/etc/sysconfig/console</filename> file for configuration + information. Decide which keymap and screen font will be used. Various + language-specific HOWTOs can also help with this, see <ulink + url="http://www.tldp.org/HOWTO/HOWTO-INDEX/other-lang.html"/>. If still in + doubt, look in the <filename class="directory">/usr/share/keymaps</filename> + and <filename class="directory">/usr/share/consolefonts</filename> directories + for valid keymaps and screen fonts. Read <filename>loadkeys(1)</filename> and + <filename>setfont(8)</filename> manual pages to determine the correct + arguments for these programs.</para> + + <para>The <filename>/etc/sysconfig/console</filename> file should contain lines + of the form: VARIABLE="value". The following variables are recognized:</para> + <variablelist> + + <varlistentry> + <term>LOGLEVEL</term> + <listitem> + <para>This variable specifies the log level for kernel messages sent + to the console as set by <command>dmesg</command>. Valid levels are + from "1" (no messages) to "8". The default level is "7".</para> + </listitem> + </varlistentry> + + <varlistentry> + <term>KEYMAP</term> + <listitem> + <para>This variable specifies the arguments for the + <command>loadkeys</command> program, typically, the name of keymap + to load, e.g., <quote>es</quote>. If this variable is not set, the + bootscript will not run the <command>loadkeys</command> program, + and the default kernel keymap will be used.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term>KEYMAP_CORRECTIONS</term> + <listitem> + <para>This (rarely used) variable + specifies the arguments for the second call to the + <command>loadkeys</command> program. This is useful if the stock keymap + is not completely satisfactory and a small adjustment has to be made. E.g., + to include the Euro sign into a keymap that normally doesn't have it, + set this variable to <quote>euro2</quote>.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term>FONT</term> + <listitem> + <para>This variable specifies the arguments for the + <command>setfont</command> program. Typically, this includes the font + name, <quote>-m</quote>, and the name of the application character + map to load. E.g., in order to load the <quote>lat1-16</quote> font + together with the <quote>8859-1</quote> application character map + (as it is appropriate in the USA), + <!-- because of the copyright sign --> + set this variable to <quote>lat1-16 -m 8859-1</quote>. + In UTF-8 mode, the kernel uses the application character map for + conversion of composed 8-bit key codes in the keymap to UTF-8, and thus + the argument of the "-m" parameter should be set to the encoding of the + composed key codes in the keymap.</para> + + </listitem> + </varlistentry> + + <varlistentry> + <term>UNICODE</term> + <listitem> + <para>Set this variable to <quote>1</quote>, <quote>yes</quote> or + <quote>true</quote> in order to put the + console into UTF-8 mode. This is useful in UTF-8 based locales and + harmful otherwise.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term>LEGACY_CHARSET</term> + <listitem> + <para>For many keyboard layouts, there is no stock Unicode keymap in + the Kbd package. The <command>console</command> bootscript will + convert an available keymap to UTF-8 on the fly if this variable is + set to the encoding of the available non-UTF-8 keymap.</para> + </listitem> + </varlistentry> + + </variablelist> + + <para>Some examples:</para> + + <itemizedlist> + + <listitem> + <para>For a non-Unicode setup, only the KEYMAP and FONT variables are + generally needed. E.g., for a Polish setup, one would use:</para> +<screen role="nodump"><userinput>cat > /etc/sysconfig/console << "EOF" +<literal># Begin /etc/sysconfig/console + +KEYMAP="pl2" +FONT="lat2a-16 -m 8859-2" + +# End /etc/sysconfig/console</literal> +EOF</userinput></screen> + </listitem> + + <listitem> + <para>As mentioned above, it is sometimes necessary to adjust a + stock keymap slightly. The following example adds the Euro symbol to the + German keymap:</para> + +<screen role="nodump"><userinput>cat > /etc/sysconfig/console << "EOF" +<literal># Begin /etc/sysconfig/console + +KEYMAP="de-latin1" +KEYMAP_CORRECTIONS="euro2" +FONT="lat0-16 -m 8859-15" + +# End /etc/sysconfig/console</literal> +EOF</userinput></screen> + </listitem> + + <listitem> + <para>The following is a Unicode-enabled example for Bulgarian, where a + stock UTF-8 keymap exists:</para> + +<screen role="nodump"><userinput>cat > /etc/sysconfig/console << "EOF" +<literal># Begin /etc/sysconfig/console + +UNICODE="1" +KEYMAP="bg_bds-utf8" +FONT="LatArCyrHeb-16" + +# End /etc/sysconfig/console</literal> +EOF</userinput></screen> + </listitem> + + <listitem> + <para>Due to the use of a 512-glyph LatArCyrHeb-16 font in the previous + example, bright colors are no longer available on the Linux console unless + a framebuffer is used. If one wants to have bright colors without + framebuffer and can live without characters not belonging to his language, + it is still possible to use a language-specific 256-glyph font, as + illustrated below:</para> + +<screen role="nodump"><userinput>cat > /etc/sysconfig/console << "EOF" +<literal># Begin /etc/sysconfig/console + +UNICODE="1" +KEYMAP="bg_bds-utf8" +FONT="cyr-sun16" + +# End /etc/sysconfig/console</literal> +EOF</userinput></screen> + </listitem> + + <listitem> + <para>The following example illustrates keymap autoconversion from + ISO-8859-15 to UTF-8 and enabling dead keys in Unicode mode:</para> + +<screen role="nodump"><userinput>cat > /etc/sysconfig/console << "EOF" +<literal># Begin /etc/sysconfig/console + +UNICODE="1" +KEYMAP="de-latin1" +KEYMAP_CORRECTIONS="euro2" +LEGACY_CHARSET="iso-8859-15" +FONT="LatArCyrHeb-16 -m 8859-15" + +# End /etc/sysconfig/console</literal> +EOF</userinput></screen> + </listitem> + + <listitem> + <para>Some keymaps have dead keys (i.e., keys that don't produce a + character by themselves, but put an accent on the character produced + by the next key) or define composition rules (such as: <quote>press + Ctrl+. A E to get Æ</quote> in the default keymap). + Linux-&linux-version; interprets dead keys and composition rules in the + keymap correctly only when the source characters to be composed together + are not multibyte. This deficiency doesn't affect keymaps for European + languages, because there accents are added to unaccented ASCII + characters, or two ASCII characters are composed together. However, in + UTF-8 mode it is a problem, e.g., for the Greek language, where one + sometimes needs to put an accent on the letter <quote>alpha</quote>. + The solution is either to avoid the use of UTF-8, or to install the + X window system that doesn't have this limitation in its input + handling.</para> + </listitem> + + <listitem> + <para>For Chinese, Japanese, Korean and some other languages, the Linux + console cannot be configured to display the needed characters. Users + who need such languages should install the X Window System, fonts that + cover the necessary character ranges, and the proper input method (e.g., + SCIM, it supports a wide variety of languages).</para> + </listitem> + + </itemizedlist> + + <!-- Added because folks keep posting their console file with X questions + to blfs-support list --> + <note> + <para>The <filename>/etc/sysconfig/console</filename> file only controls + the Linux text console localization. It has nothing to do with setting + the proper keyboard layout and terminal fonts in the X Window System, with + ssh sessions or with a serial console. In such situations, limitations + mentioned in the last two list items above do not apply.</para> + </note> + + </sect2> + + <sect2 id="ch-scripts-createfiles"> + <title>Creating Files at Boot</title> + + <indexterm zone="ch-scripts-createfiles"> + <primary sortas="d-createfiles">File creation at boot</primary> + <secondary>configuring</secondary> + </indexterm> + + <para>At times, it is desired to create files at boot time. For instance, + the <filename class="directory">/tmp/.ICE-unix</filename> directory + may be desired. This can be done by creating an entry in the + <filename>/etc/sysconfig/createfiles</filename> configuration script. + The format of this file is embedded in the comments of the default + configuration file.</para> + </sect2> + + <sect2 id="ch-scripts-sysklogd"> + <title>Configuring the sysklogd Script</title> + + <indexterm zone="ch-scripts-sysklogd"> + <primary sortas="d-sysklogd">sysklogd</primary> + <secondary>configuring</secondary> + </indexterm> + + <para>The <filename>sysklogd</filename> script invokes the + <command>syslogd</command> program as a part of System V initialization. The + <parameter>-m 0</parameter> option turns off the periodic timestamp mark that + <command>syslogd</command> writes to the log files every 20 minutes by + default. If you want to turn on this periodic timestamp mark, edit + <filename>/etc/sysconfig/rc.site</filename> and define the variable + SYSKLOGD_PARMS to the desired value. For instance, to remove all parameters, + set the variable to a null value:</para> + +<screen role="nodump">SYSKLOGD_PARMS=</screen> + + <para>See <userinput>man syslogd</userinput> for more options.</para> + + </sect2> + + <sect2 id="ch-scripts-site"> + <title>The rc.site File</title> + + <indexterm zone="ch-scripts-site"> + <primary sortas="a-rc.site">rc.site</primary> + </indexterm> + + <para>The optional <filename>/etc/sysconfig/rc.site</filename> file contains + settings that are automatically set for each SystemV boot script. It can + alternatively set the values specified in the <filename>hostname</filename>, + <filename>console</filename>, and <filename>clock</filename> files in the + <filename class='directory'>/etc/sysconfig/</filename> directory. If the + associated variables are present in both these separate files and + <filename>rc.site</filename>, the values in the script specific files have + precedence. </para> + + <para><filename>rc.site</filename> also contains parameters that can + customize other aspects of the boot process. Setting the IPROMPT variable + will enable selective running of bootscripts. Other options are described + in the file comments. The default version of the file is as follows:</para> + + <!-- Use role to fix a pdf generation problem --> + <screen role="auto">&site;</screen> + + <sect3> + <title>Customizing the Boot and Shutdown Scripts</title> + + <para>The LFS boot scripts boot and shut down a system in a fairly + efficient manner, but there are a few tweaks that you can make in the + rc.site file to improve speed even more and to adjust messages according + to your preferences. To do this, adjust the settings in + the <filename>/etc/sysconfig/rc.site</filename> file above.</para> + + <itemizedlist> + + <listitem><para>During the boot script <filename>udev</filename>, there is + a call to <command>udev settle</command> that requires some time to + complete. This time may or may not be required depending on devices present + in the system. If you only have simple partitions and a single ethernet + card, the boot process will probably not need to wait for this command. To + skip it, set the variable OMIT_UDEV_SETTLE=y.</para></listitem> + + <listitem><para>The boot script <filename>udev_retry</filename> also runs + <command>udev settle</command> by default. This command is only needed by + default if the <filename class='directory'>/var</filename> directory is + separately mounted. This is because the clock needs the file + <filename>/var/lib/hwclock/adjtime</filename>. Other customizations may + also need to wait for udev to complete, but in many installations it is not + needed. Skip the command by setting the variable OMIT_UDEV_RETRY_SETTLE=y. + </para></listitem> + + <listitem><para>By default, the file system checks are silent. This can + appear to be a delay during the bootup process. To turn on the + <command>fsck</command> output, set the variable VERBOSE_FSCK=y. + </para></listitem> + + <listitem><para>When rebooting, you may want to skip the filesystem check, + <command>fsck</command>, completely. To do this, either create the file + <filename>/fastboot</filename> or reboot the system with the command + <command>/sbin/shutdown -f -r now</command>. On the other hand, you can + force all file systems to be checked by creating + <filename>/forcefsck</filename> or running <command>shutdown</command> with + the <parameter>-F</parameter> parameter instead of <parameter>-f</parameter>. + </para> + + <para>Setting the variable FASTBOOT=y will disable <command>fsck</command> + during the boot process until it is removed. This is not recommended + on a permanent basis.</para></listitem> + + <listitem><para>Normally, all files in the <filename + class='directory'>/tmp</filename> directory are deleted at boot time. + Depending on the number of files or directories present, this can cause a + noticeable delay in the boot process. To skip removing these files set the + variable SKIPTMPCLEAN=y.</para></listitem> + + <listitem><para>During shutdown, the <command>init</command> program sends + a TERM signal to each program it has started (e.g. agetty), waits for a set + time (default 3 seconds), and sends each process a KILL signal and waits + again. This process is repeated in the <command>sendsignals</command> + script for any processes that are not shut down by their own scripts. The + delay for <command>init</command> can be set by passing a parameter. For + example to remove the delay in <command>init</command>, pass the -t0 + parameter when shutting down or rebooting (e.g. <command>/sbin/shutdown + -t0 -r now</command>). The delay for the <command>sendsignals</command> + script can be skipped by setting the parameter + KILLDELAY=0.</para></listitem> + + </itemizedlist> + + </sect3> + </sect2> </sect1> |