rwx aliyun 解决 icm off 目录 小写 识别 用户
1.1 从Sysvinit技术到Systemd技术
Sysvinit
优点:
Sysvinit运行良好,概念简单清晰。依赖于shell脚本
缺点:
1.并行启动,开机慢,
2.容易夯住(如webServer 挂载(/etc/inittab文件下) nfsServer(未启动),时,webServer会夯住。(如果写入到/etc/rc.local中,则超时后,退出脚本))
Upstart
过渡技术
Systemd
优点:并行启动,快
三种启动技术对比
1.2 并行启动原理
1.2.1 解决socket 依赖/端口依赖
系统提前创建端口,由systemd系统管家管理(个人理解),服务正常运行至开机启动后
1.2.2 解决D-Bus
依赖:采用D-Bus作为进程间的通信工具,类似消息队列,可以缓存信息
6:同步=面对面把事情交代清楚,安全性,稳定性好,速度慢
7:异步=把事情写在纸上,安全性低,速度快
1.2.3 解决文件系统依赖
autofs机制,需要时挂载
二 网卡名称
2.1 系统识别硬件的方式
7:通过网卡插槽指定网卡名称
6:通过识别硬件获得网卡名称(且每获取一次都不同)
注意:如果通过删除vm 软件删除网络适配置器。可能导致网卡插槽也会被删除!!
2.2 开机后修改网卡名称:
1. 进入到网卡配置文件目录下
- 1 cd / etc / sysconfig / network - scripts /
2.修改网卡名称
- 1 mv ifcfg - ens33 ifcfg - eth0#我的网卡原名称为ens33
3.修改网卡设备及名称
- TYPE=Ethernet
- …………
- NAME=eth0 #原为ense33 已改成eth0
- DEVICE=eth0 #原为ense33 已改成eth0
- ONBOOT=yes
- IPADDR=10.0.0.200
- PREFIX=24
- GATEWAY=10.0.0.254
- DNS1=223.5.5.5
4.修改grub配置文件
- GRUB_TIMEOUT=5
- GRUB_DISTRIBUTOR="$(sed ‘s, release .*$,,g‘ /etc/system-release)"
- GRUB_DEFAULT=saved
- GRUB_DISABLE_SUBMENU=true
- GRUB_TERMINAL_OUTPUT="console"
- GRUB_CMDLINE_LINUX="rhgb net.ifnames=0 biosdevname=0 quiet" #net.ifnames=0 biosdevname=0 为新增内容,其他不做修改
- GRUB_DISABLE_RECOVERY="true"
5.生成grub配置文件,命令
- grub2-mkconfig -o /boot/grub2/grub.cfg #执行命令
- Generating grub configuration file ... #以下为命令执行结果
- Found linux image: /boot/vmlinuz-3.10.0-693.el7.x86_64
- Found initrd image: /boot/initramfs-3.10.0-693.el7.x86_64.img
- Found linux image: /boot/vmlinuz-0-rescue-6fb9d1e602e84f5eacbc9ea411c00d80
- Found initrd image: /boot/initramfs-0-rescue-6fb9d1e602e84f5eacbc9ea411c00d80.img
- done
6.重启,查看
- reboot
- ip a s eth0
- 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 #可以直接查看网卡信息
- link/ether 00:0c:29:49:5d:cb brd ff:ff:ff:ff:ff:ff
- inet 10.0.0.200/24 brd 10.0.0.255 scope global eth0
- valid_lft forever preferred_lft forever
- inet6 fe80::20c:29ff:fe49:5dcb/64 scope link
- valid_lft forever preferred_lft forever
2.3 安装系统时修改网络配置项
- ####
- ####安装系统时修改网卡名称为eth0的方法!! 安装系统时修改网卡名称为eth0的方法!! 安装系统时修改网卡名称为eth0的方法 !!
- 3####
第3章 文件系统
7:默认为xfs 专为大数据,大文件设计
6:默认为ext4
7在安装是/boot分区选择1G,7的/boot分区需要更大
第4章 yum源优化
4.1 添加epel源
- 1 curl -o /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo
4.2 更新其他软件
- yum install -y vim wget
- yum install -y bash-completion #shell快捷帮助
- yum install -y tree lrzsz nmap nc htop #其他常用软件
五、 网络命令
7主推:ip ss
5.1 安装6系统的命令包
- ifconfig
- yum install -y net-tools
- setup
- yum install -y setuptool #废弃命令 nmtui代替 所以,我没有安装以上这些命令
5.2 主机名修改
6中主机名位置为 /etc/sysconfig/network (当时就觉得,怪异)
7中主机名位置为 /etc/hostname (这我就喜欢了)
7中修改主机名称方式与6中相同 (不做赘述)
7与6不同的地方
- . [root@centos7 ~]# hostnamectl set-hostname centos8 #修改主机名称,
- . [root@centos7 ~]# logout
- . Connection closing...Socket close.
- .
- . Connection closed by foreign host.
- .
- . Disconnected from remote host(10.0.0.200:22) at 15:27:15.
- .
- . Type `help‘ to learn how to use Xshell prompt.
- . [c:\~]$ ssh 10.0.0.200
- .
- .
- . Connecting to 10.0.0.200:22...
- . Connection established.
- . To escape to local shell, press ‘Ctrl+Alt+]‘.
- .
- . Last login: Mon Nov 13 00:26:02 2017 from 10.0.0.1
- . [root@centos8 ~]# hostname
- . centos8
- . [root@centos8 ~]# cat /etc/hostname #配置文件也被修改了
- . centos8
- . 友情提示:hostnamectl 会将所有字母转换为小写。
六、兼容/etc/rc.local
- . # Please note that you must run ‘chmod +x /etc/rc.d/rc.local‘ to ensure
- . # that this script will be executed during boot.
- .
- . touch /var/lock/subsys/local
5. 不过在最新的系统中,官方好像添加了执行权限。(官方,你好 :)
- . [root@centos7 ~]# ll /etc/rc.local
- . lrwxrwxrwx. 1 root root 13 Nov 12 06:30 /etc/rc.local -> rc.d/rc.local
3. #注意,官方还说,不建议使用shell脚本管理系统的服务 (。。。。。。)
七 行级别Runlevel
- 6中运行级别文件在 /etc/inittab文件中
- 7中运行级别文件是一个软链接
- 1. [root@centos7 system]# ll runlevel*.target #下面的软链接,是各种启动方式的软链接
- 2. lrwxrwxrwx. 1 root root 15 Nov 12 06:30 runlevel0.target -> poweroff.target
- 3. lrwxrwxrwx. 1 root root 13 Nov 12 06:30 runlevel1.target -> rescue.target
- 4. lrwxrwxrwx. 1 root root 17 Nov 12 06:30 runlevel2.target -> multi-user.target
- 5. lrwxrwxrwx. 1 root root 17 Nov 12 06:30 runlevel3.target -> multi-user.target
- 6. lrwxrwxrwx. 1 root root 17 Nov 12 06:30 runlevel4.target -> multi-user.target
- 7. lrwxrwxrwx. 1 root root 16 Nov 12 06:30 runlevel5.target -> graphical.target
- 8. lrwxrwxrwx. 1 root root 13 Nov 12 06:30 runlevel6.target -> reboot.target
- 9. [root@centos7 system]# ll default.target #这个default是一个软链接,它指向上面那个文件,就会以那种方式启动
- 10. lrwxrwxrwx. 1 root root 16 Nov 12 06:30 default.target -> graphical.target
- 1. [root@centos7 system]# systemctl get-default #显示系统配置文件中的运行级别
- 2. poweroff.target
- 3. [root@centos7 system]# systemctl set-default runlevel3.target #指定配置文件运行级别
- 4. Removed symlink /etc/systemd/system/default.target.
- 5. Created symlink from /etc/systemd/system/default.target to /usr/lib/systemd/system/multi-user.target.
- 6. [root@centos7 system]# systemctl get-default #获取配置文件运行级别
- 7. multi-user.target
八 ystemd一统天下
所有可用的单元文件存放在/usr/lib/systemd/system/ 和 /etc/systemd/system/ 目录中(后者优先级更高)
注意:目录真长,多记,多练
Systemd命令
添加图片
九 启动时间优化
- 1. [root@centos7 system]# systemd-analyze
- 2. Startup finished in 420ms (kernel)(内核加载时间) + 1.463s (initrd) (初始化进程时间) + 3.953s (userspace) (用户加载进程)= 5.837s
- 1. [root@centos7 system]# systemd-analyze blame #显示每个程序加载消耗时间
- 2. 811ms firewalld.service
- 3. 767ms dev-sda2.device
- 4. 547ms boot.mount
- 5. 445ms postfix.service
- 6. 397ms NetworkManager-wait-online.service
- 7. 247ms abrt-ccpp.service
- 8. 194ms network.service
- 9. .......
- 1. [root@centos7 ~]# systemd-analyze plot >boottime.svg #将开机时间生成svg文件,在浏览器中打开,如下图
- 2. [root@centos7 ~]# sz boottime.svg
- 在第2s后,系统开始并行启动大部分程序
拾 关闭系统服务
- . 关闭防火墙
- . [root@centos7 ~]# systemctl status firewalld.service
- . ● firewalld.service - firewalld - dynamic firewall daemon
- . Loaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled; vendor preset: enabled)
- . Active: active (running) since Sun 2017-11-12 23:51:07 CST; 1h 43min ago
- . Docs: man:firewalld(1)
- . Main PID: 807 (firewalld)
- . CGroup: /system.slice/firewalld.service
- . └─807 /usr/bin/python -Es /usr/sbin/firewalld --nofork --nopid
- .
- . Nov 12 23:51:06 localhost.localdomain systemd[1]: Starting firewalld - dynamic firewall daemon...
- . Nov 12 23:51:07 localhost.localdomain systemd[1]: Started firewalld - dynamic firewall daemon.
- . Nov 12 23:51:08 localhost.localdomain firewalld[807]: WARNING: ICMP type ‘beyond-scope‘ is not supported by the ke...pv6.
- . Nov 12 23:51:08 localhost.localdomain firewalld[807]: WARNING: beyond-scope: INVALID_ICMPTYPE: No supported ICMP t...ime.
- . Nov 12 23:51:08 localhost.localdomain firewalld[807]: WARNING: ICMP type ‘failed-policy‘ is not supported by the k...pv6.
- . Nov 12 23:51:08 localhost.localdomain firewalld[807]: WARNING: failed-policy: INVALID_ICMPTYPE: No supported ICMP ...ime.
- . Nov 12 23:51:08 localhost.localdomain firewalld[807]: WARNING: ICMP type ‘reject-route‘ is not supported by the ke...pv6.
- . Nov 12 23:51:08 localhost.localdomain firewalld[807]: WARNING: reject-route: INVALID_ICMPTYPE: No supported ICMP t...ime.
- . Hint: Some lines were ellipsized, use -l to show in full.
- . [root@centos7 ~]# systemctl is- firewalld.service
- . is-active is-enabled is-failed is-system-running
- . [root@centos7 ~]# systemctl is-enabled firewalld.service
- . enabled
- . [root@centos7 ~]# systemctl is-active firewalld.service
- . active
- . [root@centos7 ~]# systemctl is-failed firewalld.service
- . active
- . [root@centos7 ~]# systemctl stop firewalld.service #关闭防火墙(7中默认是没有使用iptables的,所以,可以yum install -y iptables.service)
- . [root@centos7 ~]# systemctl sta firewalld.service
- . start status
- . [root@centos7 ~]# systemctl status firewalld.service
- . ● firewalld.service - firewalld - dynamic firewall daemon
- . Loaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled; vendor preset: enabled)
- . Active: inactive (dead) since Mon 2017-11-13 01:40:19 CST; 9s ago
- . Docs: man:firewalld(1)
- . Main PID: 807 (code=exited, status=0/SUCCESS)
- .
- . Nov 12 23:51:06 localhost.localdomain systemd[1]: Starting firewalld - dynamic firewall daemon...
- . Nov 12 23:51:07 localhost.localdomain systemd[1]: Started firewalld - dynamic firewall daemon.
- . Nov 12 23:51:08 localhost.localdomain firewalld[807]: WARNING: ICMP type ‘beyond-scope‘ is not supported by the ke...pv6.
- . Nov 12 23:51:08 localhost.localdomain firewalld[807]: WARNING: beyond-scope: INVALID_ICMPTYPE: No supported ICMP t...ime.
- . Nov 12 23:51:08 localhost.localdomain firewalld[807]: WARNING: ICMP type ‘failed-policy‘ is not supported by the k...pv6.
- . Nov 12 23:51:08 localhost.localdomain firewalld[807]: WARNING: failed-policy: INVALID_ICMPTYPE: No supported ICMP ...ime.
- . Nov 12 23:51:08 localhost.localdomain firewalld[807]: WARNING: ICMP type ‘reject-route‘ is not supported by the ke...pv6.
- . Nov 12 23:51:08 localhost.localdomain firewalld[807]: WARNING: reject-route: INVALID_ICMPTYPE: No supported ICMP t...ime.
- . Nov 13 01:40:19 centos7 systemd[1]: Stopping firewalld - dynamic firewall daemon...
- . Nov 13 01:40:19 centos7 systemd[1]: Stopped firewalld - dynamic firewall daemon.
- . Hint: Some lines were ellipsized, use -l to show in full.
- . [root@centos7 ~]# systemctl disable firewalld.service (开机不启动防火墙)
- . Removed symlink /etc/systemd/system/multi-user.target.wants/firewalld.service.
- . Removed symlink /etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service.
- . [root@centos7 ~]# poweroff
2.关闭SELinux
同6
十一 systemd
- systemd提供更优秀的框架以表示系统服务间的依赖关系
- 实现系统初始化时服务的并行启动,同时达到降低Shell的系统开销的效果
- systemd的目标是:尽可能启动更少进程;尽可能将更多进程并行启动。
- systemd尽可能减少对shell脚本的依赖。
- 开机服务管理
- systemd添加新的unit(daemon)
- 也就是采用systemd来管理,
- /sbin/chkconfig--add foo相当
- 把新生成的foo.service放到 / usr / lib / systemd / system / 下面,然后采用load命令导入
- systemctl load foo.service
- 删除unit(daemon)
- 删除一个unit没有相应的命令,通常的做法是停掉daemon,然后删除相应的配置文件。
- 开机启动unit
- systemctl enable postfix.service
- 增加由 / usr / lib / systemd / system / 到 / etc / systemd / system / multi - user.target.wants / 下的软链接
- ln - s‘ / usr / lib / systemd / system / postfix.service‘‘ / etc / systemd / system / multi - user.target.wants / postfix.service‘
- 开机不启动unit
- systemctl disable httpd.service
- 删除 / etc / systemd / system / multi - user.target.wants下的软链接
- 查看开机是否启动
- systemctl is - enabled.service#查询服务是否开机启动
- systemd查看开机自启动的程序
- 相当于chkconfig--list
- ls / etc / systemd / system / multi - user.target.wants /
- 查看systemd单元加载及活动情况
- systemctl
- 显示启动失败的单元
- systemctl--failed
- 查看systemd管理的所有单元
- systemctl list - unit - files
- 服务管理
- === ==============================================
- 启动服务
- systemctl start httpd.service
- 关闭服务
- systemctl stop httpd.service
- 重启服务
- systemctl restart httpd.service
- 重新加载
- systemctl reload httpd.service
- 查看状态
- systemctl status httpd.service
- 包括启动状态、启动时间、主进程及相关进程、相关日志
- 运行级别
- systemd用target替代了runlevel的概念,多个的‘target‘可以同时激活
- systemd不使用 / etc / inittab,如何查看系统默认的运行级别
- ll / etc / systemd / system /
- default.target
- 查看这个软链接真正指向的文件
- 如何查看系统的当前运行级别
- runlevel依然可用
- systemd的方法是:systemctl list - units--type = target
- 改变当前target,重启无效
- systemctl isolate graphical.target
- 修改默认运行级别
- 1.首先删除已经存在的符号链接
- rm / etc / systemd / system /
- default.target
- 2.默认级别转换为3(文本模式)
- systemctl enable multi - user.target
- 相当于ln - s / lib / systemd / system / multi - user.target / etc / systemd / system /
- default.target
- 3.重启
- reboot
- 运行级别如下:
- runlevel0.target - >poweroff.target
- runlevel1.target - >rescue.target
- runlevel2.target - >multi - user.target
- runlevel3.target - >multi - user.target
- runlevel4.target - >multi - user.target
- runlevel5.target - >graphical.target
- runlevel6.target - >reboot.target
centos7新系统安装
来源: http://www.bubuko.com/infodetail-2392404.html