Linux基础

发表于
字数统计:

hosts

1
2
3
4
linux:
/etc/hosts
windows
C:\Windows\System32\drivers\etc

ssh

1
cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys

安装依赖组

1
2
3
[root@node0 ~]# yum grouplist
[root@node0 ~]# yum groupinfo 
[root@node0 ~]# yum groupinstall 开发工具

端口占用

netstat -anp|grep 80

解压缩

tar 解压缩命令 :

c: 建立压缩档案
-x：解压
-t：查看内容
-r：向压缩归档文件末尾追加文件
-u：更新原压缩包中的文件
这五个是独立的命令，压缩解压都要用到其中一个，可以和别的命令连用但只能用其中一个。下面的参数是根据需要在压缩或解压档案时可选的。
-z：有gzip属性的
-j：有bz2属性的
-Z：有compress属性的
-v：显示所有过程
-O：将文件解开到标准输出
下面的参数-f是必须的
-f: 使用档案名字，切记，这个参数是最后一个参数，后面只能接档案名。

更改主机名

查看

1
2
3
4
5
6
7
8
9
10
11
xyxj@u18_data1:~$ hostnamectl
   Static hostname: Master		#静态主机名
Transient hostname: u18_data1   #临时主机名
         Icon name: computer-vm
           Chassis: vm
        Machine ID: 67f22187487a4bbd893048a9f7b4bb13
           Boot ID: ce03c7b8874e4b75ab0bb71c886fd3fe
    Virtualization: vmware
  Operating System: Ubuntu 18.10
            Kernel: Linux 4.18.0-13-generic
      Architecture: x86-64

操作

1
2
xyxj@u18_data1:~$ sudo hostname Master-name		#更改临时主机名
xyxj@u18_data1:~$ sudo hostnamectl set-hostname Master #更改静态主机名

更改CentOS默认的yum源

1
2
3
4
5
6
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.bak
# centos-7
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo

# cache
 yum makecache

高并发和负载均衡

名词:

  • VIP: 虚拟服务器地址
  • DIP: 转发的网络地址
    • 1, 和RIP通信: ARP协议, 获取Real Server的RIP; MAC地址
    • 2.转发Client的数据包到RIP上-隐藏VIP
  • RIP: 后端真是主机
  • CIP: 客户IP地址

原则: 三次握手到四次分手不可分割

配置负载均衡

  • 准备三台centos的虚拟机

  • 配置虚拟机网络

    • eth0, 配置同一网段
    • DIP,RIP在同一网段

  • 配置lvs的VIP

    • ifconfig eth0:8 192.168.80.100/24
    • echo 1 > /proc/sys/net/ipv4/ip_forward

  • 调整RS的响应通告级别 (每台RS)

    • echo 1 > /proc/sys/net/ipv4/conf/eth0/arp_ignore
    • echo 2 > /proc/sys/net/ipv4/conf/eth0/arp_announce
    • echo 1 > /proc/sys/net/ipv4/conf/all/arp_ignore
    • echo 2 > /proc/sys/net/ipv4/conf/eth0/arp_announce

  • 配置RS的VIP

    • ifconfig lo:8 192.168.80.100 netmask 255.255.255.255 (每台RS)
    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    21
    22
    23
    24
    25
    26
    27
    28
    29
    [root@node03 ~]# ifconfig lo:8 192.168.80.100 netmask 255.255.255.255
    [root@node03 ~]# ifconfig
    eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
            inet 192.168.80.134  netmask 255.255.255.0  broadcast 192.168.80.255
            inet6 fe80::14d3:34b3:cbe:db15  prefixlen 64  scopeid 0x20<link>
            ether 00:0c:29:b5:48:2d  txqueuelen 1000  (Ethernet)
            RX packets 344  bytes 33631 (32.8 KiB)
            RX errors 0  dropped 0  overruns 0  frame 0
            TX packets 303  bytes 37666 (36.7 KiB)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

    lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
            inet 127.0.0.1  netmask 255.0.0.0
            inet6 ::1  prefixlen 128  scopeid 0x10<host>
            loop  txqueuelen 1000  (Local Loopback)
            RX packets 0  bytes 0 (0.0 B)
            RX errors 0  dropped 0  overruns 0  frame 0
            TX packets 0  bytes 0 (0.0 B)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

    lo:8: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
            inet 192.168.80.100  netmask 255.255.255.255
            loop  txqueuelen 1000  (Local Loopback)
            
    [root@node03 ~]# route -n
    Kernel IP routing table
    Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
    0.0.0.0         192.168.80.2    0.0.0.0         UG    100    0        0 eth0
    192.168.80.0    0.0.0.0         255.255.255.0   U     100    0        0 eth0

注意: 如果-bash: ifconfig: 未找到命令

yum upgrade | yum install net-tools

此时centos的网络是ens33不是eth0, 看下网卡符号:

1
2
3
4
5
6
7
8
9
en　　以太网　　　　Ethernet
wl　　无线局域网　　WLAN
ww　  无线广域网　　WWAN
# 第三个符号
o<index>           on-board device index number
s<slot>            hotplug slot index number
x<MAC>             MAC address
p<bus>s<slot>      PCI geographical location
p<bus>s<slot>      USB port number chain

更改ens33为eth0

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
[root@node01 ~]# ifconfig -a
ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.80.133  netmask 255.255.255.0  broadcast 192.168.80.255
        inet6 fe80::37e7:f8eb:43c2:b25d  prefixlen 64  scopeid 0x20<link>
        ether 00:0c:29:ad:18:5f  txqueuelen 1000  (Ethernet)
        RX packets 68  bytes 8216 (8.0 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 102  bytes 11726 (11.4 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

[root@node01 ~]# vim /etc/sysconfig/grub 
# GRUB_CMDLINE_LINUX="...net.ifnames=0 biosdevname=0 rhgb quiet" 添加
# GRUB_CMDLINE_LINUX="crashkernel=auto rd.lvm.lv=centos/root rd.lvm.lv=centos/swap net.ifnames=0 biosdevname=0 rhgb quiet"
[root@node01 ~]# grub2-mkconfig -o /boot/grub2/grub.cfg
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-3.10.0-957.1.3.el7.x86_64
Found initrd image: /boot/initramfs-3.10.0-957.1.3.el7.x86_64.img
Found linux image: /boot/vmlinuz-3.10.0-957.el7.x86_64
Found initrd image: /boot/initramfs-3.10.0-957.el7.x86_64.img
Found linux image: /boot/vmlinuz-0-rescue-fc191819a9854dbba98e8e06dbe41ee2
Found initrd image: /boot/initramfs-0-rescue-fc191819a9854dbba98e8e06dbe41ee2.img
done
[root@node01 ~]# cp /etc/sysconfig/network-scripts/ifcfg-ens33 /etc/sysconfig/network-scripts/ifcfg-ens33.bak

[root@node01 ~]# mv /etc/sysconfig/network-scripts/ifcfg-ens33 /etc/sysconfig/network-scripts/ifcfg-eth0

[root@node01 ~]# vim /etc/sysconfig/network-scripts/ifcfg-eth0

[root@node01 ~]# ls /etc/sysconfig/network-scripts/
ifcfg-ens33.bak  ifdown-eth   ifdown-ppp       ifdown-tunnel  ifup-ippp   ifup-post    ifup-TeamPort      network-functions-ipv6
ifcfg-eth0       ifdown-ippp  ifdown-routes    ifup           ifup-ipv6   ifup-ppp     ifup-tunnel
ifcfg-lo         ifdown-ipv6  ifdown-sit       ifup-aliases   ifup-isdn   ifup-routes  ifup-wireless
ifdown           ifdown-isdn  ifdown-Team      ifup-bnep      ifup-plip   ifup-sit     init.ipv6-global
ifdown-bnep      ifdown-post  ifdown-TeamPort  ifup-eth       ifup-plusb  ifup-Team    network-functions

[root@node01 ~]# systemctl restart network.service
Job for network.service failed because the control process exited with error code. See "systemctl status network.service" and "journalctl -xe" for details.

[root@node01 ~]# systemctl status network.service

出错了,重启虚拟机, 这个时候的网卡名称已经更改,虚拟IP地址也更改了.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
[root@node01 ~]# ifconfig
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.80.135  netmask 255.255.255.0  broadcast 192.168.80.255
        inet6 fe80::3e9a:38cd:a02:a4c6  prefixlen 64  scopeid 0x20<link>
        ether 00:0c:29:ad:18:5f  txqueuelen 1000  (Ethernet)
        RX packets 76  bytes 8657 (8.4 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 108  bytes 12252 (11.9 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

  • 在rs上启动httpd

    • yum install httpd -y
    • cd /var/www/html
      • vim index.html
      • from 如果id ip
    • systemctl start httpd.service
      • 验证 RIP
      • VIP不显示

    如果访问不到就需要关闭虚拟机的防火墙

    1
    systemctl stop firewalld.service

  • 配置lvs

    • yum install ipvsadm -y
    • ipvsadm -A -t 192.168.80.100:80 -s rr
    • ipvsadm -a -t 192.168.80.100:80 -r 192.168.80.134 -g
    • ipvsadm -a -t 192.168.80.100:80 -r 192.168.80.136 -g
    • ipvsadm -ln
    • 浏览器刷新
    • ipvsadm -lnc
    • netstat -natp

Keepalived

解决单点故障

删除多余内核

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
# look
[root@node01 ~]# uname -sr
Linux 3.10.0-957.1.3.el7.x86_64
[root@node01 ~]# rpm -qa | grep kernel
kernel-tools-libs-3.10.0-957.1.3.el7.x86_64
kernel-tools-3.10.0-957.1.3.el7.x86_64
kernel-3.10.0-957.1.3.el7.x86_64
kernel-headers-3.10.0-957.1.3.el7.x86_64
kernel-3.10.0-957.el7.x86_64
[root@node01 ~]# rpm -e kernel-3.10.0-957.el7.x86_64
[root@node01 ~]# rpm -qa | grep kernel
kernel-tools-libs-3.10.0-957.1.3.el7.x86_64
kernel-tools-3.10.0-957.1.3.el7.x86_64
kernel-3.10.0-957.1.3.el7.x86_64
kernel-headers-3.10.0-957.1.3.el7.x86_64
[root@node01 ~]#
Donate comment here