Linux: Linux启动和内核管理

# 查看unit支持的资源类型
[root@centos8-A ~]#systemctl -t help
Available unit types:
service                  #服务
socket                   #套接字
target                   #runlevel运行模式
device                   #设备
mount                  #挂载
automount
swap                     #交换分区
timer                     #计数器
path
slice
scope

# socket ip 端口
[root@ali-bj-prod-web001 ~]# yum install telnet-server
[root@ali-bj-prod-web001 ~]# systemctl start  telnet.socket
[root@ali-bj-prod-web001 ~]# systemctl status telnet.socket
● telnet.socket - Telnet Server Activation Socket
   Loaded: loaded (/usr/lib/systemd/system/telnet.socket; disabled; vendor preset: disabled)
   Active: active (listening) since Sat 2021-02-27 07:25:12 CST; 2s ago

# 检查 telnet服务并没有启动，而systemd启动一个23端口
[root@ali-bj-prod-web001 ~]# ps -ef|grep telnet 
root        1655    1339  0 07:25 pts/0    00:00:00 grep --color=auto telnet
[root@ali-bj-prod-web001 ~]# ss -tnlp   #可以看到23端口由systemd监控
State         Recv-Q        Send-Q               Local Address:Port               Peer Address:Port    
LISTEN        0             128                              *:23                            *:*            users:(("systemd",pid=1,fd=24))                  
[root@ali-bj-prod-web001 ~]# lsof -i :23
COMMAND PID USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
systemd   1 root   24u  IPv6  29270      0t0  TCP *:telnet (LISTEN)

# windows远程 23端口 
[c:\~]$ telnet 182.92.4.110 23
Connecting to 182.92.4.110:23.
Connection established.
To escape to local shell, press Ctrl+Alt+].

# 再检查，telnet服务启动
[root@ali-bj-prod-web001 ~]# lsof -i :23
COMMAND    PID USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
systemd      1 root   19u  IPv6  29811      0t0  TCP ali-bj-prod-web001:telnet->120.244.188.76:30963 (ESTABLISHED)
systemd      1 root   24u  IPv6  29270      0t0  TCP *:telnet (LISTEN)
in.telnet 1666 root    0u  IPv6  29811      0t0  TCP ali-bj-prod-web001:telnet->120.244.188.76:30963 (ESTABLISHED)
in.telnet 1666 root    1u  IPv6  29811      0t0  TCP ali-bj-prod-web001:telnet->120.244.188.76:30963 (ESTABLISHED)
in.telnet 1666 root    2u  IPv6  29811      0t0  TCP ali-bj-prod-web001:telnet->120.244.188.76:30963 (ESTABLISHED)
[root@ali-bj-prod-web001 ~]# ps -ef|grep telnet 
root        1666       1  0 07:26 ?        00:00:00 in.telnetd: ::ffff:120.244.188.76

# socket与服务程序分离
[root@ali-bj-prod-web001 ~]# yum install rpcbind -y
[root@ali-bj-prod-web001 ~]# rpm -ql rpcbind
/usr/lib/systemd/system/rpcbind.service
/usr/lib/systemd/system/rpcbind.socket
[root@ali-bj-prod-web001 ~]# systemctl start   rpcbind.socket
[root@ali-bj-prod-web001 ~]# ps -ef|grep rpcbind
root        1905    1339  0 07:31 pts/0    00:00:00 grep --color=auto rpcbind
[root@ali-bj-prod-web001 ~]# ss -tnlp   #可以看到111端口由systemd监控
LISTEN        0             128                        0.0.0.0:111                     0.0.0.0:*            users:(("systemd",pid=1,fd=108))   

[root@ali-bj-prod-web001 ~]# lsof -i :111
COMMAND PID USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
systemd   1 root  108u  IPv4  30718      0t0  TCP *:sunrpc (LISTEN)
systemd   1 root  109u  IPv4  30719      0t0  UDP *:sunrpc 
systemd   1 root  110u  IPv6  30720      0t0  TCP *:sunrpc (LISTEN)
systemd   1 root  111u  IPv6  31745      0t0  UDP *:sunrpc 


# windows远程 23端口 
[c:\~]$ telnet 182.92.4.110 111
Connecting to 182.92.4.110:111.
Connection established.
To escape to local shell, press Ctrl+Alt+].

[root@ali-bj-prod-web001 ~]# ps -ef|grep rpcbind
rpc         1961       1  3 07:33 ?        00:00:00 /usr/bin/rpcbind -w -f
root        1976    1339  0 07:33 pts/0    00:00:00 grep --color=auto rpcbind

[root@ali-bj-prod-web001 ~]# systemctl status  rpcbind
● rpcbind.service - RPC Bind
   Loaded: loaded (/usr/lib/systemd/system/rpcbind.service; enabled; vendor preset: enabled)
   Active: active (running) since Sat 2021-02-27 07:33:04 CST; 5s ago
     Docs: man:rpcbind(8)
 Main PID: 1961 (rpcbind)
    Tasks: 1 (limit: 4652)
   Memory: 996.0K
   CGroup: /system.slice/rpcbind.service
           └─1961 /usr/bin/rpcbind -w -f

Feb 27 07:33:03 ali-bj-prod-web001 systemd[1]: Starting RPC Bind...
Feb 27 07:33:04 ali-bj-prod-web001 systemd[1]: Started RPC Bind.

/usr/lib/systemd/system         #每个服务最主要的启动脚本设置，类似于之前的/etc/init.d/
/lib/systemd/system                #ubutun的对应目录，兼容于CentOS7,8和Ubuntu

/run/systemd/system              #系统执行过程中所产生的服务脚本，比上面目录优先运行
/etc/systemd/system               #管理员建立的执行脚本，类似于/etc/rcN.d/Sxx的功能，比上面目录优先运行

systemctl COMMAND name.service

##setp1
#启动：相当于service name start 
systemctl start name1.service  name2.service   

#停止：相当于service name stop
systemctl stop name.service

#重启：相当于service name restart 
systemctl restart name.service 

#查看状态：相当于service name status
systemctl status name.service

##setp2
#禁止自动和手动启动：
systemctl mask name.service # 把 /etc/systemd/system/下的软连接文件指向/dev/null

#取消禁止
systemctl unmask name.service

#查看某服务当前激活与否的状态：
systemctl is-active name.service    #没有启动，返回状态码为非0。启动返回状态码为0

#查看service文件内容
systemctl cat name.service

#查看所有已经激活的服务：
systemctl list-units --type|-t service

#查看所有服务：
systemctl list-units --type service --all|-a

##setp3
#设定某服务开机自启，相当于chkconfig name on 
systemctl enable name.service 

#设定某服务开机禁止启动：相当于chkconfig name off
systemctl disable name.service

#查看是否开机启动
systemctl is-enabled name.service

#开机并立即启动或停止
systemctl enable --now postfix 
systemctl disable  --now postfix

##setp4
#查看所有服务的开机自启状态，相当于chkconfig --list
systemctl list-unit-files --type service

#用来列出该服务在哪些运行级别下启用和禁用：chkconfig –list name
ls /etc/systemd/system/*.wants/name.service

#列出失败的服务
systemctl --failed --type=service

#查看服务的依赖关系：
systemctl list-dependencies name.service

#杀掉进程：
systemctl kill unitname

#显示状态
systemctl list-unit-files --type service --all

#显示所有单元状态
systemctl 或 systemctl list-units
#只显示服务单元的状态
systemctl --type=service
#显示sshd服务单元
systemctl –l status sshd.service
#验证sshd服务当前是否活动
systemctl is-active sshd
#启动，停止和重启sshd服务
systemctl start sshd.service
systemctl stop sshd.service
systemctl restart sshd.service

#重新加载配置
systemctl reload sshd.service
#列出活动状态的所有服务单元
systemctl list-units --type=service
#列出所有服务单元
systemctl list-units --type=service --all
#查看服务单元的启用和禁用状态
systemctl list-unit-files --type=service

#列出依赖的单元
systemctl list-dependencies sshd
验证sshd服务是否开机启动
systemctl is-enabled sshd
禁用network，使之不能自动启动,但手动可以
systemctl disable network

#启用network
systemctl enable network

#禁用network，使之不能手动或自动启动
systemctl mask network

#启用network
systemctl unmask network

[root@centos8 ~]#head -n 5 /lib/systemd/system/postfix.service 
[Unit]
Description=Postfix Mail Transport Agent
After=syslog.target network.target
Conflicts=sendmail.service exim.service

systemctl daemon-reload

[Unit]
Description=The Nginx HTTP Server daemon # 描述信息
After=network.target remote-fs.target nss-lookup.target 
# 指定启动nginx之前需要其他的其他服务，如network.target等

[Service]
# Type为服务类型，仅启动一个主进程的服务为simple，需要启动若干子进程的服务为forking
Type=forking 

# 设置执行systemctl start nginx后需要启动的具体命令
ExecStart=/usr/local/nginx/sbin/nginx

# 设置执行systemctl reload nginx后需要执行的具体命令
ExecReload=/usr/local/nginx/sbin/nginx -s reload

# 设置执行systemctl stop nginx后需要执行的具体命令
ExecStop=/bin/kill -s QUIT ${MAINPID}

[Install]
# 设置在什么模式下被安装，设置开机启动的时候需要
WantedBy=multi-user.target

[root@ip-10-0-133-61 ~]#  systemctl cat kubelet
# /etc/systemd/system/kubelet.service
[Unit]
Description=Kubernetes Kubelet
Documentation=https://github.com/kubernetes/kubernetes
After=containerd.service sandbox-image.service
Requires=containerd.service sandbox-image.service

[Service]
Slice=runtime.slice
ExecStartPre=/sbin/iptables -P FORWARD ACCEPT -w 5
ExecStart=/usr/bin/kubelet \
    --config /etc/kubernetes/kubelet/kubelet-config.json \
    --kubeconfig /var/lib/kubelet/kubeconfig \
    --container-runtime-endpoint unix:///run/containerd/containerd.sock \
    --image-credential-provider-config /etc/eks/image-credential-provider/config.json \
    --image-credential-provider-bin-dir /etc/eks/image-credential-provider \
    $KUBELET_ARGS \
    $KUBELET_EXTRA_ARGS

Restart=on-failure
RestartForceExitStatus=SIGPIPE
RestartSec=5
KillMode=process
CPUAccounting=true
MemoryAccounting=true

[Install]
WantedBy=multi-user.target

# /etc/systemd/system/kubelet.service.d/10-kubelet-args.conf
[Service]
Environment='KUBELET_ARGS=--node-ip=10.0.133.61 --pod-infra-container-image=8770xxxx.dkr.ecr.af-south-1.amazonaws.com/eks/pause:3.5 --v=2 --hostname-override=ip-10-0-133-61.af-south-1
# /etc/systemd/system/kubelet.service.d/30-kubelet-extra-args.conf
[Service]
Environment='KUBELET_EXTRA_ARGS=--node-labels=eks.amazonaws.com/sourceLaunchTemplateVersion=8,eks.amazonaws.com/nodegroup-image=ami-0660eafe04534cc32,eks.amazonaws.com/capacityType=ON_DEM

vim /usr/lib/systemd/system/tomcat.service 
[Unit]
Description=java tomcat project
After=syslog.target network.target

[Service]
Type=forking
EnvironmentFile=/usr/local/tomcat/conf/tomcat.conf
ExecStart=/usr/local/tomcat/bin/startup.sh
ExecStop=/usr/local/tomcat/bin/shutdown.sh
PrivateTmp=true
User=tomcat

[Install]
WantedBy=multi-user.target

[root@test jasper]# systemctl  cat nginx
# /usr/lib/systemd/system/nginx.service
[Unit]
Description=nginx - high performance web server
Documentation=http://nginx.org/en/docs/
After=network-online.target remote-fs.target nss-lookup.target
Wants=network-online.target

[Service]
Type=forking
PIDFile=/var/run/nginx.pid
ExecStart=/usr/sbin/nginx -c /etc/nginx/nginx.conf
ExecReload=/bin/sh -c "/bin/kill -s HUP $(/bin/cat /var/run/nginx.pid)"
ExecStop=/bin/sh -c "/bin/kill -s TERM $(/bin/cat /var/run/nginx.pid)"

[Install]
WantedBy=multi-user.target

cat >/usr/lib/systemd/system/nginx.service<<\EOF
[Unit]
Description=The NGINX HTTP and reverse proxy server
Documentation=http://nginx.org/en/docs/
After=network-online.target remote-fs.target nss-lookup.target
Wants=network-online.target

[Service]
Type=forking
PIDFile=/usr/local/nginx/logs/nginx.pid
ExecStartPre=/usr/local/nginx/sbin/nginx -t
ExecStart=/usr/local/nginx/sbin/nginx
ExecReload=/usr/local/nginx/sbin/nginx -s reload
#ExecReload=/bin/kill -s HUP $MAINPID
ExecStop=/bin/kill -s QUIT $MAINPID
PrivateTmp=true
LimitNOFILE=infinity

[Install]
WantedBy=multi-user.target
EOF
systemctl daemon-reload
systemctl enable nginx


＃修改权限
$ sudo chmod +x /usr/lib/systemd/system/nginx.service
＃/etc/systemd/system/multi-user.target.wants/
$ sudo systemctl enable nginx.service
#现在可以使用下面的指令来控制nginx啦
$ sudo systemctl start nginx.service
$ sudo systemctl reload nginx.service
$ sudo systemctl restart nginx.service
$ sudo systemctl stop nginx.service
#日志
$ journalctl -f -u nginx.service

[root@master01 ~]# cat /usr/lib/systemd/system/zookeeper.service
[Unit]
Description=Apache ZooKeeperPI
After=network.target
ConditionPathExists=/etc/zookeeper/conf/zoo.cfg
ConditionPathExists=/etc/zookeeper/conf/log4j.properties

[Service]
Environment="ZOOCFGDIR=/etc/zookeeper/conf"
SyslogIdentifier=zookeeper
WorkingDirectory=/opt/mesosphere/zookeeper
ExecStart=/opt/mesosphere/zookeeper/bin/zkServer.sh start-foreground
Restart=on-failure
RestartSec=20
User=root
Group=root

[Install]
WantedBy=multi-user.target

[Unit]
Description=Java Service

[Service]
User=pfg
WorkingDirectory=/gamepind/rummy/rummy-pot
Environment=LOG_DIR=/gamepind/rummy/rummy-pot
ExecStart=/usr/local/java/bin/java  -XX:MetaspaceSize=128m -XX:MaxMetaspaceSize=128m -XX:+HeapDumpOnOutOfMemoryError -Xms4g -Xmx4g  -Xss256k  -XX:+UseG1GC -XX:MaxGCPauseMillis=200 -XX:+PrintGCTimeStamps -XX:+PrintGCDateStamps -XX:+PrintGCDetails -Xloggc:/gamepind/rummy/rummy-pot/logs/gc.log -jar rummy-pot.jar
SuccessExitStatus=143
TimeoutStopSec=10
Restart=on-failure
RestartSec=5
LimitNOFILE = 200000

[Install]
WantedBy=multi-user.target

root@ubuntu1804 ~]#ll /lib/systemd/system/rc.local.service 
lrwxrwxrwx 1 root root 16 Dec 12  2018 /lib/systemd/system/rc.local.service -> 
rc-local.service
[root@ubuntu1804 ~]#grep -v "^#" /lib/systemd/system/rc.local.service 
[Unit]
Description=/etc/rc.local Compatibility
Documentation=man:systemd-rc-local-generator(8)
ConditionFileIsExecutable=/etc/rc.local
After=network.target

[Service]
Type=forking
ExecStart=/etc/rc.local start
TimeoutSec=0
RemainAfterExit=yes
GuessMainPID=no

[root@ubuntu1804 ~]#vim /etc/rc.local
[root@ubuntu1804 ~]#cat /etc/rc.local
#!/bin/bash
echo -e '\E[31;1mstarting test service\E[0m'
sleep 10
[root@ubuntu1804 ~]#chmod +x /etc/rc.local
[root@ubuntu1804 ~]#reboot

cp /lib/systemd/system/memcached.service /lib/systemd/system/[email protected]

[Unit]
Description=Memcached
Before=httpd.service
After=network.target

[Service]
Type=simple
EnvironmentFile=-/etc/sysconfig/memcached%i
ExecStart=/usr/bin/memcached -u $USER -p $PORT -m $CACHESIZE -c $MAXCONN $OPTIONS

[Install]
WantedBy=multi-user.target

systemctl start memcached@1 在service文件里用%i来接受参数

systemctl enable [email protected]
systemctl enable [email protected]
[root@xu-2 sysconfig]# systemctl list-unit-files|grep enable|grep memcached
[email protected]   

当 systemd 查找单元文件时，会首先查找与单元名称完全吻合的单元文件， 如果没有找到，并且单元名称中包含 "@" 字符， 那么 systemd 将会继续查找拥有相同前缀的模板文件， 如果找到，那么将从这个模板文件实例化一个单元来使用。 例如，对于 [email protected] 单元来说， 其对应的模板文件是 [email protected] (也就是去掉 "@" 与后缀名之间的部分)。
systemctl enable --now memcached@2

ls /usr/lib/systemd/system/*.target
systemctl list-unit-files --type target --all

0 ==> runlevel0.target, poweroff.target
1 ==> runlevel1.target, rescue.target
2 ==> runlevel2.target, multi-user.target
3 ==> runlevel3.target, multi-user.target
4 ==> runlevel4.target, multi-user.target
5 ==> runlevel5.target, graphical.target
6 ==> runlevel6.target, reboot.target
0：关机
1：单用户模式(root自动登录), single, 维护模式
2：多用户模式，启动网络功能，但不会启动NFS；维护模式
3：多用户模式，正常模式；文本界面
4：预留级别；可同3级别
5：多用户模式，正常模式；图形界面
6：重启

systemctl list-dependencies graphical.target

systemctl isolate name.target

systemctl default  

#切换至字符模式
systemctl isolate multi-user.target

systemctl get-default

systemctl set-default name.target

[root@centos8 ~]#systemctl set-default multi-user.target
[root@centos8 ~]#ls -l /etc/systemd/system/default.target
lrwxrwxrwx. 1 root root 37 Nov 7 19:32 /etc/systemd/system/default.target -> 
/lib/systemd/system/multi-user.target

systemctl rescue

systemctl emergency

#关机
systemctl halt、systemctl poweroff

#重启：
systemctl reboot

#挂起：
systemctl suspend

#休眠：
systemctl hibernate

#休眠并挂起：
systemctl hybrid-sleep

[root@centos8 ~]#ls -l /lib/systemd/system/ctrl-alt-del.target    
lrwxrwxrwx. 1 root root 13 May 23 2019 /lib/systemd/system/ctrl-alt-del.target 
-> reboot.target
[root@centos8 ~]#systemctl mask ctrl-alt-del.target 
Created symlink /etc/systemd/system/ctrl-alt-del.target → /dev/null.

[root@centos8 ~]#init q  #相当于systemctl daemon-reload 重新加载启动文件
[root@centos8 ~]#systemctl daemon-reload

systemd.unit=multi-user.target
systemd.unit=emergency.target
systemd.unit=rescue.target

systemctl list-dependencies multi-user.target

systemd-analyze time #启动时间 
systemd-analyze blame # 详细启动内容
systemd-analyze plot >bootime.svg # 生成图片
systemd-analyze plot > boot.html # 生成网页

[root@centos8-A ~]#systemd-analyze blame
         46.797s dnf-makecache.service
          5.789s kdump.service
          5.370s tuned.service
          5.110s postfix.service
          3.551s systemd-udev-settle.service
          2.837s sssd.service
          2.753s vdo.service
          2.240s NetworkManager-wait-online.service
          1.982s systemd-machined.service
          1.958s plymouth-quit.service
          1.913s plymouth-quit-wait.service
          1.755s lvm2-monitor.service
          1.501s polkit.service
          1.481s systemd-resolved.service
          1.391s dracut-initqueue.service
          1.288s systemd-logind.service
          1.183s ModemManager.service
          1.120s libvirtd.service
          1.025s cockpit-motd.service
          1.004s rsyslog.service
           985ms avahi-daemon.service
           737ms initrd-switch-root.service
           675ms bluetooth.service
           652ms systemd-journald.service
           629ms NetworkManager.service
           531ms gssproxy.service
           528ms cups.service
           ......
            58ms rpcbind.service
            56ms systemd-fsck-root.service
            55ms rpc-statd-notify.service
            49ms date.mount
            48ms systemd-rfkill.service
            45ms cockpit.socket
            43ms import-state.service
            38ms dracut-pre-udev.service
            31ms plymouth-switch-root.service
            30ms systemd-tmpfiles-setup.service
            29ms sys-kernel-config.mount
            26ms systemd-journal-flush.service
            26ms systemd-tmpfiles-clean.service
            25ms systemd-update-utmp-runlevel.service
            24ms initrd-udevadm-cleanup-db.service
            22ms initrd-cleanup.service
            18ms plymouth-read-write.service
            10ms systemd-update-utmp.service
             8ms sysstat-collect.service
             7ms dracut-shutdown.service

systemd-analyze plot > boot.html

启动时任意键暂停启动
按e键进入编辑模式
将光标移动linux 开始的行，添加内核参数rd.break 打破正常启动
按ctrl-x启动
mount –o remount,rw /sysroot
chroot /sysroot
passwd root

#如果SELinux是启用的,才需要执行下面操作,如查没有启动,不需要执行
touch /.autorelabel

exit
reboot

启动时任意键暂停启动
按e键进入编辑模式
将光标移动linux 开始的行，改为rw init=/sysroot/bin/sh
按ctrl-x启动
chroot /sysroot
passwd root

#如果SELinux是启用的,才需要执行下面操作,如查没有启动,不需要执行
touch /.autorelabel

exit
reboot

#添加grub密码，会在/boot/grub2/下生成user.cfg文件
[root@centos8 ~]#grub2-setpassword
Enter password: 
Confirm password: 

[root@centos8 ~]#ls -l /boot/grub2/
total 32
drwxr-xr-x 2 root root  4096 Jan 19 15:17 fonts
-rw-r--r-- 1 root root  5101 Jan 19 15:18 grub.cfg
-rw-r--r-- 1 root root  1024 Jan 19 15:18 grubenv
drwxr-xr-x 2 root root 12288 Jan 19 15:17 i386-pc
-rw------- 1 root root   298 Jan 19 18:20 user.cfg
[root@centos8 ~]#ls -l /boot/grub2/user.cfg 
-rw------- 1 root root 298 Jan 19 18:20 /boot/grub2/user.cfg
[root@centos8 ~]#cat /boot/grub2/user.cfg
GRUB2_PASSWORD=grub.pbkdf2.sha512.10000.60AAA29A65F4DC77E8861EF25BDE2034C9B30CE1
E07EE688D7F30460E7E87E7356B0893A6DFFB250B27D2EB9D3ED3E9207199C494D7882E2E8C772C8
2E2DDB7A.5E42FD69FA04293DECD68F077E83875A8E4572A7FBB89BA9F161B15EAFE54FBA963FE5D
52E16764944823396231803E5118DA1D9CAF3EB73C175A7D7A3682A90

#清空grub密码
[root@centos8 ~]#cat /dev/null > /boot/grub2/user.cfg

grub2-install /dev/sda #BIOS环境
grub2-install #UEFI环境

[root@centos8-A ~]#cat /boot/grub2/grubenv 
# GRUB Environment Block
saved_entry=b74f53e89700498b96f22ddee0f70ced-4.18.0-147.el8.x86_64  # 可手动修改为想启动的内核内容，适合centos8
kernelopts=root=UUID=6498b37b-cbbf-4771-8327-b65704274aef ro crashkernel=auto resume=UUID=8424a27b-4f74-4249-b229-0ba992a5c4e7 rhgb quiet net.ifnames=0 
boot_success=0
boot_indeterminate=0
#############################################################

[root@centos8-A ~]#ls /boot/loader/entries/
b74f53e89700498b96f22ddee0f70ced-0-rescue.conf  
b74f53e89700498b96f22ddee0f70ced-4.18.0-147.el8.x86_64.conf

#以下命令是修改 /boot/grub2/grubenv 实现 适合centos7
[root@centos8 ~]#grub2-set-default 1  
#或者
[root@centos8 ~]#vim /etc/default/grub 
GRUB_DEFAULT=1

-n: 显示节点名称
-r: 显示VERSION-RELEASE
-a:显示所有信息

[root@centos8 ~]#lsmod 
Module                 Size Used by
uas                    28672  0
usb_storage            73728  1 uas
nls_utf8               16384  0
isofs                  45056  0 #显示：名称、大小，使用次数，被哪些模块依赖

modinfo [ -k kernel ] [ modulename|filename... ]

-n：只显示模块文件路径；相对于-F filename
-p：显示模块参数
-a：作者
-d：描述
-F field：仅显示指定字段的信息；
-k kernel：多内核并存时若要查询另外一个kernel上的模块信息

[root@centos8-A ~]#lsmod |grep xfs
xfs                  1474560  2
libcrc32c              16384  3 nf_conntrack,nf_nat,xfs
[root@centos8-A ~]#modinfo xfs
filename:       /lib/modules/4.18.0-147.el8.x86_64/kernel/fs/xfs/xfs.ko.xz
license:        GPL
description:    SGI XFS with ACLs, security attributes, no debug enabled
author:         Silicon Graphics, Inc.
alias:          fs-xfs
rhelversion:    8.1
srcversion:     947E2EDC226CFCEC0F1F71B
depends:        libcrc32c
intree:         Y
name:           xfs
vermagic:       4.18.0-147.el8.x86_64 SMP mod_unload modversions 
sig_id:         PKCS#7
signer:         CentOS Linux kernel signing key
sig_key:        79:05:D0:5C:21:6F:8A:C5:DD:6E:19:BB:77:9D:05:F6:F2:21:B8:17
sig_hashalgo:   sha256
signature:      C9:68:71:F6:2D:2A:F9:83:AC:A8:12:30:29:E3:61:1C:0C:2F:1E:7E:
        BC:1D:87:B9:56:00:4E:6F:87:9C:6F:22:78:09:D1:D9:C0:D0:21:C1:
        8F:0F:62:11:C0:15:E5:6E:70:D4:A5:92:F7:15:D8:0F:C4:4E:F4:7E:
        87:74:A9:32:CC:D7:97:1B:11:B9:3C:98:51:25:DD:99:1D:15:55:19:
        C2:E4:67:58:AE:A0:7F:21:13:3C:F5:A1:8B:86:81:70:49:3F:62:3B:
        F0:37:A9:8F:87:01:5D:7F:FA:5C:5A:1F:16:88:EE:87:DA:03:8C:9D:
        92:7E:5E:F4:D6:56:AF:FF:DB:FA:8A:AC:D3:BE:2F:13:7A:1D:CB:BF:
        A5:EB:2C:06:2C:7D:55:E6:AA:78:83:51:F4:CA:72:98:79:C1:55:E4:
        80:C2:8D:4F:E5:CB:EC:A4:9D:AB:5A:AA:CB:8A:A5:FE:0C:E1:CC:1E:
        26:A3:D1:E7:FA:F4:D2:66:12:1F:BB:4F:73:16:8A:A0:19:7E:A5:17:
        3D:DF:2A:A5:B2:4F:64:44:2B:3E:06:A1:3A:5F:FF:DD:CC:6B:71:20:
        A8:6E:83:AF:A6:C0:38:B6:3A:C3:72:2F:74:64:1F:E4:1C:EC:E5:B4:
        77:AA:5D:38:3B:50:EB:1A:82:79:13:7C:A6:70:B1:37:A0:1E:4C:18:
        C9:14:46:7A:0B:D4:2F:A3:29:E6:49:42:D4:A8:03:4F:33:FA:D7:3E:
        C4:CE:F7:53:C7:1D:7F:28:4F:70:F5:67:71:29:2E:9C:E5:A6:60:02:
        D2:49:7F:F1:6D:3D:E6:F9:FF:B0:01:F8:C2:50:C3:AB:23:50:F4:19:
        A2:45:DC:9B:C3:1C:DA:C0:36:88:7C:C0:9B:D7:7D:B6:3A:D5:83:AD:
        AD:7A:33:92:09:D2:7F:B0:0E:B4:21:2F:DB:F9:F7:50:E4:C8:94:D1:
        29:E6:2D:C1:5D:51:94:14:1C:72:04:CB:BF:FC:DA:6E:A3:66:D2:0A:
        C5:E0:F2:0F

modprobe [ -C config-file ] [ modulename ] [ module parame-ters... ] 
modprobe [ -r ] modulename… 卸载
同时会挂载依赖的模块

[root@centos8-A ~]#lsmod |grep usb
btusb                  53248  0
btrtl                  16384  1 btusb
btbcm                  16384  1 btusb
btintel                24576  1 btusb
bluetooth             630784  27 btrtl,btintel,btbcm,bnep,btusb,rfcomm
[root@centos8-A ~]#modprobe usb_storage
[root@centos8-A ~]#lsmod |grep usb
usb_storage            73728  0
btusb                  53248  0
btrtl                  16384  1 btusb
btbcm                  16384  1 btusb
btintel                24576  1 btusb
bluetooth             630784  27 btrtl,btintel,btbcm,bnep,btusb,rfcomm
[root@centos8-A ~]#modprobe -r usb_storage
[root@centos8-A ~]#lsmod |grep uas

#因为uas依赖usb_storage,安装uas会自动加载usb_storage
[root@centos8-A ~]#modprobe uas
[root@centos8-A ~]#lsmod |grep usb
usb_storage            73728  1 uas
btusb                  53248  0
btrtl                  16384  1 btusb
btbcm                  16384  1 btusb
btintel                24576  1 btusb
bluetooth             630784  27 btrtl,btintel,btbcm,bnep,btusb,rfcomm
[root@centos8-A ~]#lsmod |grep -E 'usb|uas'
uas                    28672  0
usb_storage            73728  1 uas
btusb                  53248  0
btrtl                  16384  1 btusb
btbcm                  16384  1 btusb
btintel                24576  1 btusb
bluetooth             630784  27 btrtl,btintel,btbcm,bnep,btusb,rfcomm

#因为uas依赖usb_storage，无法直接卸载usb_storage
[root@centos8-A ~]#modprobe -r usb_storage
modprobe: FATAL: Module usb_storage is in use.

[root@centos8-A ~]#modprobe -r uas
[root@centos8-A ~]#modprobe -r usb_storage

insmod [ filename ] [ module options... ]

insmod `modinfo –n exportfs`
insmod `modinfo –n xfs`

rmmod [ modulename ]

rmmod xfs
rmmod exportfs

cat /proc/cpuinfo
x86info -a
lscpu

[root@centos7 ~]# lspci #查看当前PCI设备
00:00.0 Host bridge: Intel Corporation 440BX/ZX/DX - 82443BX/ZX/DX Host bridge (rev 01)
00:01.0 PCI bridge（北桥）: Intel Corporation 440BX/ZX/DX - 82443BX/ZX/DX AGP bridge (rev 01)
00:07.0 ISA bridge（南桥）: Intel Corporation 82371AB/EB/MB PIIX4 ISA (rev 08)
00:07.1 IDE interface(IDE接口): Intel Corporation 82371AB/EB/MB PIIX4 IDE (rev 01)
00:07.3 Bridge(高级电源管理桥): Intel Corporation 82371AB/EB/MB PIIX4 ACPI (rev 08)
00:07.7 System peripheral（集成接口）: VMware Virtual Machine Communication Interface (rev 10)
00:0f.0 VGA compatible controller（显卡接口）: VMware SVGA II Adapter
00:10.0 SCSI storage controller（存储控制器）: LSI Logic / Symbios Logic 53c1030 PCI-X Fusion-MPT Dual Ultra320 SCSI (rev 01)
... ...
00:18.7 PCI bridge: VMware PCI Express Root Port (rev 01)
02:00.0 USB controller: VMware USB1.1 UHCI Controller（型号UHCI，USB1.1控制器）
02:01.0 Ethernet controller: Intel Corporation 82545EM Gigabit Ethernet Controller (Copper) (rev 01)（千兆以太网网控制器）
02:02.0 Multimedia audio controller: Ensoniq ES1371 / Creative Labs CT2518 [AudioPCI-97] (rev 02)
02:03.0 USB controller: VMware USB2 EHCI Controller（型号EHCI，USB2控制器）

[root@centos8-A ~]#dnf install usbutils -y
[root@centos8-A ~]#lsusb
Bus 001 Device 004: ID 0951:1666 Kingston Technology DataTraveler 100 G3/G4/SE9 
G2
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 003: ID 0e0f:0002 VMware, Inc. Virtual USB Hub
Bus 002 Device 002: ID 0e0f:0003 VMware, Inc. Virtual Mouse
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
[root@centos8-A ~]#lsmod |grep usb
usb_storage           73728 1 uas

[ ]: N
[M]: M  # 独立模块核心文件
[*]: Y  # 打包到内核文件中

获取源代码
tar xf linux-
cd /usr/src
ln -sv linux-3.10.67 linux  #编译驱动时通常会找linux目录，这里创建个软连接
cd linux
make menuconfig             #配置内核选项
make [-j #]                 #编译内核，可使用-j指定编译线程数据流
make modules_install        #安装内核模块
make install                #安装内核
重启系统，选择使用新内核；

# 安装依赖
[root@centos8 ~]#yum -y install gcc make ncurses-devel flex bison openssl-devel elfutils-libelf-devel
# 下载内核
[root@centos8 ~]#tar xf linux-5.6.12.tar.xz -C /usr/local/src
[root@centos8 ~]#cd /usr/local/src
[root@centos8 ~]#ln -sv linux-5.6.12 linux

# 编译
[root@centos8 ~]#cd /usr/src/linux
[root@centos8 linux]#cp /boot/config-$(uname -r)   ./.config
[root@centos8 linux]#vim .config 
#修改下面两行，CentOS7无需修改
# CONFIG_MODULE_SIG is not set
CONFIG_SYSTEM_TRUSTED_KEYS=""

[root@centos8 linux]#make help
[root@centos8 linux]#make menuconfig  #大窗口才能显示
[root@centos8 linux]#time make -j $(nproc)  # nproc 获取CPU个数
#或者两步实现：make -j 2 bzImage ; make -j 2 modules
......
 LD [M] sound/xen/snd_xen_front.ko
 LD [M] virt/lib/irqbypass.ko

real 82m52.128s
user 133m37.982s
sys 25m46.311s
[root@centos8 linux]#pwd
/usr/local/src/linux
[root@centos8 linux]#du -sh .
15G .
[root@centos8 linux]#make modules_install
[root@centos8 linux]#ls /lib/modules
4.18.0-147.el8.x86_64  5.6.12-cuilinux-6.6.6
[root@centos8 linux]#du -sh /lib/modules/5.6.12-cuilinux-6.6.6/
3.5G /lib/modules/5.6.12-cuilinux-6.6.6/

[root@centos8 linux]#make install  #  会自动修改grub信息
[root@centos8 linux]#ls /boot
System.map-4.18.0-147.el8.x86_64
System.map-5.6.12-cuilinux-6.6.6
vmlinuz-5.6.12-cuilinux-6.6.6

[root@centos8 ~]#ls /boot/loader/entries/ 
5b85fc7444b240a992c42ce2a9f65db5-0-rescue.conf
5b85fc7444b240a992c42ce2a9f65db5-5.6.12-cuilinux-6.6.6.conf
[root@centos8 ~]#cat /boot/loader/entries/5b85fc7444b240a992c42ce2a9f65db5-5.6.12-cuilinux-6.6.6.conf 
title CentOS Linux (5.6.12-cuilinux-6.6.6) 8 (Core)
version 5.6.12-cuilinux-6.6.6
linux /vmlinuz-5.6.12-cuilinux-6.6.6
initrd /initramfs-5.6.12-cuilinux-6.6.6.img $tuned_initrd
options $kernelopts $tuned_params
id centos-20200513060531-5.6.12-cuilinux-6.6.6
grub_users $grub_users
grub_arg --unrestricted
grub_class kernel

[root@centos8 ~]#reboot 
[root@centos8 ~]#uname -r
5.6.12-cuilinux-6.6.6

cc1: error: -Werror=date-time: no option -Wdate-time
# 4.9以及之后的gcc版本中才有这两个选项，如果你在gcc版本小于4.9的系统上编译，比如在centos7.2系统中，centos中默认的gcc版本是4.8.5，编译时就会报"cc1: 错误：-Werror=date-time：没有选项 -Wdate-time"错误，所以这种解决方法如果只是使用4.9以上的gcc版本是没有问题的；

# 方法1 升级gcc 4.9
yum install bzip2 -y
wget -P /usr/src https://mirrors.aliyun.com/gnu/gcc/gcc-10.2.0/gcc-10.2.0.tar.gz
cd /usr/src && tar -xzvf gcc-10.2.0.tar.gz
cd gcc-10.2.0/ && ./contrib/download_prerequisites # 配置依赖项
#这一步可能国内会等待比较久，耐心等待
#如果报错其他文件不能下载，去https://gcc.gnu.org/pub/gcc/infrastructure/下载对应文件，复制到/usr/src/gcc-10.2.0即可

#创建安装文件夹和编译文件夹
mkdir /usr/lib/gcc/x86_64-redhat-linux/10.2.0
mkdir /usr/src/gcc-build-10.2.0

# 配置安装文件
cd /usr/src/gcc-10.2.0
./configure --prefix=/usr/lib/gcc/x86_64-redhat-linux/10.2.0/ --enable-checking=release --enable-languages=c,c++ --disable-multilib

# 执行编译并安装(编译需要2-3小时，请耐心等待)
time make -j $(nproc) && make install

# 备份原gcc并链接新gcc
mv /usr/bin/gcc /usr/bin/gcc-4.8.5
mv /usr/bin/g++ /usr/bin/g++-4.8.5
alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.8.5 88 --slave /usr/bin/g++ g++ /usr/bin/g++-4.8.5
alternatives --install /usr/bin/gcc gcc /usr/lib/gcc/x86_64-redhat-linux/10.2.0/bin/x86_64-pc-linux-gnu-gcc 99 --slave /usr/bin/g++ g++ /usr/lib/gcc/x86_64-redhat-linux/10.2.0/bin/x86_64-pc-linux-gnu-g++
alternatives --config gcc

# 查询版本
gcc -v
g++ -v

# 如果出现错误
/lib64/libstdc++.so.6: version `GLIBCXX_3.4.21' not found
/lib64/libstdc++.so.6: version `GLIBCXX_3.4.22' not found
#执行链接新的libstdc++.so.6库文件
rm -f /usr/lib64/libstdc++.so.6
ln -s /usr/lib/gcc/x86_64-redhat-linux/10.2.0/lib64/libstdc++.so.6 /usr/lib64/libstdc++.so.6
#可以用以下指令查看目前包含哪些库
strings /usr/lib64/libstdc++.so.6 | grep GLIBC

make [-j #]

cd /usr/src/linux; make dir/

cd /usr/src/linux; make dir/file.ko

make drivers/net/ethernet/intel/e1000/e1000.ko

make ARCH=arm help

make clean：清理大多数编译生成的文件，但会保留.config文件等
make mrproper: 清理所有编译生成的文件、config及某些备份文件
make distclean：包含 make mrproper,并清理patches以及编辑器备份文件

[root@centos7 ~]#yum -y install   gcc gcc-c++ glibc glibc-devel make pcre pcredevel openssl openssl-devel systemd-devel zlib-devel glibc-static ncurses-devel

[root@centos7 ~]#wget https://busybox.net/downloads/busybox-1.31.1.tar.bz2

[root@centos7 ~]#tar xvf busybox-1.31.1.tar.bz2 
[root@centos7 ~]#cd busybox-1.31.1/
[root@centos7 busybox-1.31.1]#make menuconfig 
#按下面选择，把busybox编译也静态二进制、不用共享库:Settings -->Build Options -->[*] Build static binary (no shared libs)

[root@centos7 busybox-1.31.1]#make 
#如果出错，执行make clean后，重新执行上面命令
[root@centos7 busybox-1.31.1]#ls 
[root@centos7 busybox-1.31.1]#make install 
[root@centos7 busybox-1.31.1]#pwd
/root/busybox-1.31.1
[root@Centos7 busybox-1.31.1]#ls
applets                 debianutils  loginutils              qemu_multiarch_testing
applets_sh              docs         mailutils               README
arch                    e2fsprogs    Makefile                runit
archival                editors      Makefile.custom         scripts
AUTHORS                 examples     Makefile.flags          selinux
busybox                 findutils    Makefile.help           shell
busybox.links           include      make_single_applets.sh  size_single_applets.sh
busybox_unstripped      init         miscutils               sysklogd
busybox_unstripped.map  _install     modutils                testsuite
busybox_unstripped.out  INSTALL      networking              TODO
Config.in               klibc-utils  NOFORK_NOEXEC.lst       TODO_unicode
configs                 libbb        NOFORK_NOEXEC.sh        util-linux
console-tools           libpwdgrp    printutils
coreutils               LICENSE      procps
[root@Centos7 busybox-1.31.1]#ll busybox -h
-rwxr-xr-x 1 root root 2.6M May 14 09:35 busybox

[root@Centos7 busybox-1.31.1]#ls _install/
bin  linuxrc  sbin  usr
[root@Centos7 busybox-1.31.1]#ls _install/bin
arch     cttyhack       fdflush   kbd_mode  mknod       ping           run-parts     tar
ash      date           fgrep     kill      mktemp      ping6          scriptreplay  touch
base64   dd             fsync     link      more        pipe_progress  sed           true
busybox  df             getopt    linux32   mount       printenv       setarch       umount
cat      dmesg          grep      linux64   mountpoint  ps             setpriv       uname
chattr   dnsdomainname  gunzip    ln        mpstat      pwd            setserial     usleep
chgrp    dumpkmap       gzip      login     mt          reformime      sh            vi
chmod    echo           hostname  ls        mv          resume         sleep         watch
chown    ed             hush      lsattr    netstat     rev            stat          zcat
conspy   egrep          ionice    lzop      nice        rm             stty
cp       false          iostat    makemime  nuke        rmdir          su
cpio     fatattr        ipcalc    mkdir     pidof       rpm            sync

[root@Centos7 busybox-1.31.1]#find _install/ -type l |wc -l
396
[root@Centos7 busybox-1.31.1]#du -sh _install/
2.6M    _install/

[root@Centos7 busybox-1.31.1]#mkdir /mnt/sysroot/
[root@Centos7 busybox-1.31.1]#cp -a _install/* /mnt/sysroot/

#分两个必要的分区,/dev/sdb1对应/boot   /dev/sdb2对应根 /
[root@centos6 ~]#echo -e 'n\np\n1\n\n+1G\nw\n' | fdisk /dev/sdb
[root@centos6 ~]#echo -e 'n\np\n2\n\n\n\nw\n' | fdisk /dev/sdb
[root@centos6 ~]#mkfs.ext4 /dev/sdb1
[root@centos6 ~]#mkfs.ext4 /dev/sdb2

#子目录必须为boot
[root@centos6 ~]#mkdir /mnt/boot
[root@centos6 ~]#mount /dev/sdb1 /mnt/boot

[root@centos6 ~]#grub-install --root-directory=/mnt/ /dev/sdb

[root@centos6 ~]#cp /boot/vmlinuz-2.6.32-754.el6.x86_64 /mnt/boot/vmlinuz
[root@centos6 ~]#cp /boot/initramfs-2.6.32-754.el6.x86_64.img /mnt/boot/initramfs.img

[root@centos6 ~]#cat /mnt/boot/grub/grub.conf
default=0
timeout=5
title cui linux 
root (hd0,0)
kernel /vmlinuz root=/dev/sda2 selinux=0 init=/bin/bash
initrd /initramfs.img

# root=/dev/sda2 对于要启动的系统而言
[root@centos6 ~]#tree /mnt/boot
/mnt/boot
├── grub
│   ├── device.map
│   ├── e2fs_stage1_5
│   ├── fat_stage1_5
│   ├── ffs_stage1_5
│   ├── grub.conf
│   ├── iso9660_stage1_5
│   ├── jfs_stage1_5
│   ├── minix_stage1_5
│   ├── reiserfs_stage1_5
│   ├── stage1
│   ├── stage2
│   ├── ufs2_stage1_5
│   ├── vstafs_stage1_5
│   └── xfs_stage1_5
├── initramfs-2.6.32-754.el6.x86_64.img
├── lost+found
└── vmlinuz.img

2 directories, 16 files

[root@centos6 ~]#mkdir /mnt/sysroot
[root@centos6 ~]#mount /dev/sdb2   /mnt/sysroot
[root@centos6 ~]#mkdir –pv /mnt/sysroot/{boot,dev,sys,proc,etc,lib,lib64,bin,sbin,tmp,var,usr,opt,home,root,mnt,media}
#复制bash等命令和相关库文件，如：
bash,ifconfig,insmod,ping,mount,ls,cat,df,lsblk,blkid,tree,fdisk

[root@centos6 ~]#mkdir /mnt/sysroot/{dev,proc,etc,sys,lib,home,root}
for i in $(ldd /bin/bash | grep -o '/[^[:space:]]\+[0-9]\>'); do cp $i /mnt/sysroot/lib64 ;done

#准备网卡驱动
[root@centos6 ~]#ethtool -i eth0
driver: e1000
version: 7.3.21-k8-NAPI
firmware-version: 
bus-info: 0000:02:01.0
supports-statistics: yes
supports-test: yes
supports-eeprom-access: yes
supports-register-dump: yes
supports-priv-flags: no
[root@centos6 ~]#modinfo e1000
filename:/lib/modules/2.6.32-754.el6.x86_64/kernel/drivers/net/e1000/e1000.ko

[root@centos6 ~]#cp /lib/modules/2.6.32-754.el6.x86_64/kernel/drivers/net/e1000/e1000.ko /mnt/sysroot/lib/

[root@centos6 ~]#chroot /mnt/sysroot/
bash-4.1# pwd
/