Centos7系统配置上的变化（一）

原文 Centos7系统配置上的变化（一）

安装后，一开始有点儿无力吐槽的感觉，变化这么大？

一、Runlevel 首先一条，原来一直用的CentOS-6.5-x86_64-minimal.iso光盘镜像（400M左右无图形系统小巧便捷），而7目前最小的镜像是CentOS-7.0-1406-x86_64-livecd.iso（700M左右），默认安装后是启动图形界面，按原来的习惯要改成启动命令行，结果发现：

view sourceprint?

01.[root@localhost ~]# cat /etc/inittab

02.# inittab is no longer used when using systemd.

03.#

04.# ADDING CONFIGURATION HERE WILL HAVE NO EFFECT ON YOUR SYSTEM.

05.#

06.# Ctrl-Alt-Delete is handled by /etc/systemd/system/ctrl-alt-del.target

07.#

08.# systemd uses ‘targets‘ instead of runlevels. By default, there are two main targets:

09.#

10.# multi-user.target: analogous to runlevel 3

11.# graphical.target: analogous to runlevel 5

12.#

13.# To set a default target, run:

14.#

15.# ln -sf /lib/systemd/system/<target name>.target /etc/systemd/system/default.target

16.#

好吧，systemd一统天下了（它管的东西很多很多，学Centos7首先要搞定systemd）。

view sourceprint?

1.[root@localhost ~]# ls -Xl /etc/systemd/system/*.target

2.lrwxrwxrwx. 1 root root 36 7月 8 23:12 /etc/systemd/system/default.target -> /lib/systemd/system/graphical.target

我们来看看从前的runlevel都变成什么样了？

view sourceprint?

01.[root@localhost ~]# ls -Xl /lib/systemd/system

02.[root@localhost ~]# ls -Xl /lib/systemd/system/runlevel*.target

03.lrwxrwxrwx. 1 root root 15 7月 5 00:45 /lib/systemd/system/runlevel0.target -> poweroff.target

04.lrwxrwxrwx. 1 root root 13 7月 5 00:45 /lib/systemd/system/runlevel1.target -> rescue.target

05.lrwxrwxrwx. 1 root root 17 7月 5 00:45 /lib/systemd/system/runlevel2.target -> multi-user.target

06.lrwxrwxrwx. 1 root root 17 7月 5 00:45 /lib/systemd/system/runlevel3.target -> multi-user.target

07.lrwxrwxrwx. 1 root root 17 7月 5 00:45 /lib/systemd/system/runlevel4.target -> multi-user.target

08.lrwxrwxrwx. 1 root root 16 7月 5 00:45 /lib/systemd/system/runlevel5.target -> graphical.target

09.lrwxrwxrwx. 1 root root 13 7月 5 00:45 /lib/systemd/system/runlevel6.target -> reboot.target

修改默认启动runlevel为 multi-user （貌似runlevel2 3 4 没区别了）

view sourceprint?

1.[root@localhost ~]# ln -sf /lib/systemd/system/multi-user.target /etc/systemd/system/default.target

2.[root@localhost ~]# ll -X /etc/systemd/system/*.target

3.lrwxrwxrwx. 1 root root 37 7月 10 09:42 /etc/systemd/system/default.target -> /lib/systemd/system/multi-user.target

试试init 6 还好用不。

view sourceprint?

1.[root@localhost ~]# init 6

2.Connection to 192.168.150.180 closed by remote host.

3.Connection to 192.168.150.180 closed.

成，好用。:)

因为我从桌面版Linux 连接Centos7系统提示变成了中文，所以需要把Centos7 的root用户语言改一下，回到原汁原味。

view sourceprint?

1.[root@localhost ~]# cp .bashrc .bashrc-back

2.[root@localhost ~]# echo ‘export LANG="en_Us.UTF-8"‘ >> /root/.bashrc

二、Services

view sourceprint?

01.[root@localhost ~]# chkconfig

02.

03.Note: This output shows SysV services only and does not include native

04.systemd services. SysV configuration data might be overridden by native

05.systemd configuration.

06.

07.If you want to list systemd services use ‘systemctl list-unit-files‘.

08.To see services enabled on particular target use

09.‘systemctl list-dependencies [target]‘.

10.

11.iprdump            0:off    1:off    2:on    3:on    4:on    5:on    6:off

12.iprinit            0:off    1:off    2:on    3:on    4:on    5:on    6:off

13.iprupdate          0:off    1:off    2:on    3:on    4:on    5:on    6:off

14.livesys            0:off    1:off    2:off    3:on    4:on    5:on    6:off

15.livesys-late       0:off    1:off    2:off    3:on    4:on    5:on    6:off

16.netconsole         0:off    1:off    2:off    3:off    4:off    5:off    6:off

17.network            0:off    1:off    2:off    3:off    4:off    5:off    6:off

18.rhnsd              0:off    1:off    2:on    3:on    4:on    5:on    6:off

19.vboxadd            0:off    1:off    2:on    3:on    4:on    5:on    6:off

20.vboxadd-service    0:off    1:off    2:on    3:on    4:on    5:on    6:off

21.vboxadd-x11        0:off    1:off    2:off    3:on    4:off    5:on    6:off

SysV已经快退居二线了，想配置服务得用systemctl，先看看默认启动的服务吧。（如果不用grep过滤一下，输出结果有260多行）

view sourceprint?

01.[root@localhost ~]# systemctl list-unit-files|grep enabled

02.tmp.mount                                   enabled

03.accounts-daemon.service                     enabled

04.atd.service                                 enabled

05.auditd.service                              enabled

06.avahi-daemon.service                        enabled

07.bluetooth.service                           enabled

08.chronyd.service                             enabled

09.crond.service                               enabled

10.dbus-org.bluez.service                      enabled

11.dbus-org.fedoraproject.FirewallD1.service   enabled

12.dbus-org.freedesktop.Avahi.service          enabled

13.dbus-org.freedesktop.NetworkManager.service enabled

14.dbus-org.freedesktop.nm-dispatcher.service  enabled

15.display-manager.service                     enabled

16.dmraid-activation.service                   enabled

17.firewalld.service                           enabled

18.gdm.service                                 enabled

19.[email protected]                              enabled

20.irqbalance.service                          enabled

21.iscsi.service                               enabled

22.kdump.service                               enabled

23.libstoragemgmt.service                      enabled

24.lvm2-monitor.service                        enabled

25.mdmonitor.service                           enabled

26.microcode.service                           enabled

27.multipathd.service                          enabled

28.NetworkManager-dispatcher.service           enabled

29.NetworkManager.service                      enabled

30.packagekit-offline-update.service           enabled

31.postfix.service                             enabled

32.rngd.service                                enabled

33.rsyslog.service                             enabled

34.rtkit-daemon.service                        enabled

35.smartd.service                              enabled

36.spice-vdagentd.service                      enabled

37.sysstat.service                             enabled

38.systemd-readahead-collect.service           enabled

39.systemd-readahead-drop.service              enabled

40.systemd-readahead-replay.service            enabled

41.tuned.service                               enabled

42.avahi-daemon.socket                         enabled

43.dm-event.socket                             enabled

44.iscsid.socket                               enabled

45.iscsiuio.socket                             enabled

46.lvm2-lvmetad.socket                         enabled

47.default.target                              enabled

48.multi-user.target                           enabled

49.remote-fs.target                            enabled

默认居然没有启动sshd，晕！看看监听端口：

view sourceprint?

1.[root@localhost ~]# netstat -lntp

2.Active Internet connections (only servers)

3.Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name   

4.tcp        0      0 127.0.0.1:25            0.0.0.0:*               LISTEN      2090/master

果然没有22，试试老办法：

view sourceprint?

1.[root@localhost ~]# chkconfig sshd on

2.Note: Forwarding request to ‘systemctl enable sshd.service‘.

3.ln -s ‘/usr/lib/systemd/system/sshd.service‘ ‘/etc/systemd/system/multi-user.target.wants/sshd.service‘

能用，但是指令被转发到 systemctl enable sshd.service ，以后控制服务就用这个指令了。试试：

禁用sshd：

view sourceprint?

1.[root@localhost ~]# systemctl disable sshd.service

2.rm ‘/etc/systemd/system/multi-user.target.wants/sshd.service‘

启用sshd:

view sourceprint?

1.[root@localhost ~]# systemctl enable sshd.service

2.ln -s ‘/usr/lib/systemd/system/sshd.service‘ ‘/etc/systemd/system/multi-user.target.wants/sshd.service‘

看看：

view sourceprint?

01.[root@localhost ~]# systemctl list-unit-files|grep sshd.service

02.anaconda-sshd.service                       static

03.sshd.service                                enabled

04.

05.[root@localhost ~]# netstat -lntp

06.Active Internet connections (only servers)

07.Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name   

08.tcp        0      0 127.0.0.1:25            0.0.0.0:*               LISTEN     2090/master        

09.tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN     2758/sshd          

10.tcp6       0      0 :::22                   :::*                    LISTEN      2758/sshd

其实启用和禁用服务就是在当前“runlevel”的配置文件目录（/etc/systemd/system/multi-user.target.wants/）里，

建立/usr/lib/systemd/system 里面对应服务配置文件的软链接；禁用服务就是删除此软链接。 有兴趣就自己看看 /usr/lib/systemd/system 里的文件，语法跟旧版/etc/init.d/ 里的服务脚本完全不同，也不能再用 /etc/init.d/sshd restart 之类的指令启动服务器了。

先试试旧方法启动服务：

view sourceprint?

1.[root@localhost ~]# service sshd start

2.Redirecting to /bin/systemctl start  sshd.service

用新方法折腾一下：

view sourceprint?

1.[root@localhost ~]# systemctl start sshd.service

2.[root@localhost ~]# systemctl stop sshd.service

3.[root@localhost ~]# systemctl restart sshd.service

4.[root@localhost ~]#

如果没有错误，就不会输出任何信息，这个，，，，得习惯一下。

三、网络 setup工具还是保留了，但有区别，没有了网络配置，多了RHN（Centos到底是跟RedHat一家子了） [[email protected] ~]# setup

好吧，我们看看网络配置。

view sourceprint?

01.[root@localhost ~]# cat /etc/resolv.conf

02.# Generated by NetworkManager

03.nameserver 192.168.150.254

04.

05.[root@localhost ~]# cat /etc/sysconfig/network

06.# Created by anaconda

07.

08.[root@localhost ~]# ll /etc/sysconfig/network-scripts/ifcfg-*

09.-rw-r--r--. 1 root root 298 Jul  9 00:13 /etc/sysconfig/network-scripts/ifcfg-Auto_Ethernet

10.-rw-r--r--. 1 root root 288 Jul  8 23:12 /etc/sysconfig/network-scripts/ifcfg-enp0s3

11.-rw-r--r--. 1 root root 254 Apr  2 23:30 /etc/sysconfig/network-scripts/ifcfg-lo

12.

13.[root@localhost ~]# ifconfig

14.enp0s3: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500

15.inet 192.168.150.180  netmask 255.255.255.0  broadcast 192.168.150.255

16.inet6 fe80::a00:27ff:fe9a:a688  prefixlen 64  scopeid 0x20<link>

17.ether 08:00:27:9a:a6:88  txqueuelen 1000  (Ethernet)

18.RX packets 39317  bytes 2487945 (2.3 MiB)

19.RX errors 0  dropped 0  overruns 0  frame 0

20.TX packets 2216  bytes 740115 (722.7 KiB)

21.TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

22.

23.lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536

24.inet 127.0.0.1  netmask 255.0.0.0

25.inet6 ::1  prefixlen 128  scopeid 0x10<host>

26.loop  txqueuelen 0  (Local Loopback)

27.RX packets 6  bytes 504 (504.0 B)

28.RX errors 0  dropped 0  overruns 0  frame 0

29.TX packets 6  bytes 504 (504.0 B)

30.TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

31.

32.[root@localhost ~]#

先改改主机名：

view sourceprint?

1.[root@localhost ~]# echo "hostname cenots7.localdomain" >>/etc/sysconfig/network

2.[root@localhost ~]# reboot

3.Connection to 192.168.150.180 closed by remote host.

4.Connection to 192.168.150.180 closed.

5.xw@Opt9010:~$ ssh root@192.168.150.180

6.root@192.168.150.180‘s pass<a href="http://www.it165.net/edu/ebg/" target="_blank"class="keylink">word</a>:

7.Last login: Thu Jul 10 10:01:09 2014

8.[root@cenots7 ~]#

看看网卡配置文件：

view sourceprint?

01.[root@cenots7 ~]# cd /etc/sysconfig/network-scripts/

02.

03.[root@cenots7 network-scripts]# cat ifcfg-Auto_Ethernet

04.HWADDR=08:00:27:9A:A6:88

05.TYPE=Ethernet

06.BOOTPROTO=dhcp

07.DEFROUTE=yes

08.PEERDNS=yes

09.PEERROUTES=yes

10.IPV4_FAILURE_FATAL=no

11.IPV6INIT=yes

12.IPV6_AUTOCONF=yes

13.IPV6_DEFROUTE=yes

14.IPV6_PEERDNS=yes

15.IPV6_PEERROUTES=yes

16.IPV6_FAILURE_FATAL=no

17.NAME="Auto Ethernet"

18.UUID=76304098-8f46-4185-8337-bb7f0d90423e

19.ONBOOT=yes

20.

21.[root@cenots7 network-scripts]# cat ifcfg-enp0s3

22.HWADDR=08:00:27:9A:A6:88

23.TYPE=Ethernet

24.BOOTPROTO=dhcp

25.DEFROUTE=yes

26.PEERDNS=yes

27.PEERROUTES=yes

28.IPV4_FAILURE_FATAL=no

29.IPV6INIT=yes

30.IPV6_AUTOCONF=yes

31.IPV6_DEFROUTE=yes

32.IPV6_PEERDNS=yes

33.IPV6_PEERROUTES=yes

34.IPV6_FAILURE_FATAL=no

35.NAME=enp0s3

36.UUID=66a635c2-9600-437b-8cfb-57e9569f68da

37.ONBOOT=no

看看两个文件有啥不同：

view sourceprint?

01.[root@cenots7 network-scripts]# diff ifcfg-Auto_Ethernet ifcfg-enp0s3

02.14,16c14,16

03.< NAME="Auto Ethernet"

04.< UUID=76304098-8f46-4185-8337-bb7f0d90423e

05.< ONBOOT=yes

06.---

07.> NAME=enp0s3

08.> UUID=66a635c2-9600-437b-8cfb-57e9569f68da

09.> ONBOOT=no

两个文件MAC地址一样，ifcfg-Auto_Ethernet ONBOOT=yes，但是ifconfig结果显示的是enp0s3，有点儿费解了。

再看看我复制KVM虚拟机时经常要改的网卡MAC地址：

view sourceprint?

01.root@cenots7 network-scripts]# ll /etc/udev/rules.d/

02.total 8

03.-rw-r--r--. 1 root root 134 Jul  9 00:47 60-vboxadd.rules

04.-rw-r--r--. 1 root root 352 Jul  4 00:38 98-kexec.rules

05.

06.[root@cenots7 network-scripts]# cat /etc/udev/rules.d/98-kexec.rules

07.SUBSYSTEM=="cpu", ACTION=="online", PROGRAM="/bin/systemctl try-restart kdump.service"

08.SUBSYSTEM=="cpu", ACTION=="offline", PROGRAM="/bin/systemctl try-restart kdump.service"

09.SUBSYSTEM=="memory", ACTION=="add", PROGRAM="/bin/systemctl try-restart kdump.service"

10.SUBSYSTEM=="memory", ACTION=="remove", PROGRAM="/bin/systemctl try-restart kdump.service"

11.

12.[root@cenots7 network-scripts]# cat /etc/udev/rules.d/60-vboxadd.rules

13.KERNEL=="vboxguest", NAME="vboxguest", OWNER="vboxadd", MODE="0660"

14.KERNEL=="vboxuser", NAME="vboxuser", OWNER="vboxadd", MODE="0666"

70-persistent-net.rules呢？

网卡MAC只在网卡配置文件里有，一旦变了我只需要改网卡配置文件？

view sourceprint?

1.[root@cenots7 network-scripts]# grep -r "08:00:27:9A:A6:88" /etc/

2./etc/sysconfig/network-scripts/ifcfg-enp0s3:HWADDR=08:00:27:9A:A6:88

3./etc/sysconfig/network-scripts/ifcfg-Auto_Ethernet:HWADDR=08:00:27:9A:A6:88

改一下网卡MAC 0800279AA688 -> 0800278C3746

改MAC后网卡不认了，测试结果是只需要改网卡配置文件的MAC，而且两个配置文件都要改才行。我顺便把DHCP改成了固定IP。

view sourceprint?

01.[root@cenots7 ~]# cat /etc/sysconfig/network-scripts/ifcfg-Auto_Ethernet

02.HWADDR=08:00:27:8C:37:46

03.# HWADDR=08:00:27:9A:A6:88

04.TYPE=Ethernet

05.BOOTPROTO=static

06.IPADDR=192.168.150.180

07.NETMASK=255.255.255.0

08.GATEWAY=192.168.150.254

09.DEFROUTE=yes

10.PEERDNS=yes

11.PEERROUTES=yes

12.IPV4_FAILURE_FATAL=no

13.IPV6INIT=no

14.IPV6_AUTOCONF=no

15.IPV6_DEFROUTE=no

16.IPV6_PEERDNS=no

17.IPV6_PEERROUTES=no

18.IPV6_FAILURE_FATAL=no

19.NAME="Auto Ethernet"

20.UUID=76304098-8f46-4185-8337-bb7f0d90423e

21.ONBOOT=yes

22.

23.[root@cenots7 ~]# cat /etc/sysconfig/network-scripts/ifcfg-enp0s3

24.HWADDR=08:00:27:8C:37:46

25.# HWADDR=08:00:27:9A:A6:88

26.TYPE=Ethernet

27.BOOTPROTO=static

28.IPADDR=192.168.150.180

29.NETMASK=255.255.255.0

30.GATEWAY=192.168.150.254

31.DEFROUTE=yes

32.PEERDNS=yes

33.PEERROUTES=yes

34.IPV4_FAILURE_FATAL=no

35.IPV6INIT=no

36.IPV6_AUTOCONF=no

37.IPV6_DEFROUTE=no

38.IPV6_PEERDNS=no

39.IPV6_PEERROUTES=no

40.IPV6_FAILURE_FATAL=no

41.NAME=enp0s3

42.UUID=66a635c2-9600-437b-8cfb-57e9569f68da

43.ONBOOT=no

好吧，这样初步解决了基础问题。回头见。。。。