ubuntu基础环境设置

Posted 2022-03-27 小怪獣55

​1.root账户登陆​

#1.设置root账户密码
tao@ubuntu:~$ sudo passwd root
[sudo] password for tao:   #输入当前用户密码
Enter new UNIX password: 
Retype new UNIX password: 
passwd: password updated successfully

#2.
sudo vim /etc/ssh/sshd_config
-----------------------------------
PermitRootLogin yes

#3.
systemctl restart sshd

​2.修改网卡名​

#1.
root@ubuntu:~# cat /etc/default/grub |grep GRUB_CMDLINE_LINUX_DEFAULT
GRUB_CMDLINE_LINUX_DEFAULT=""
root@ubuntu:~# sed -ri  /^GRUB_CMDLINE_LINUX_DEFAULT/s@(.*)"$@\\1net.ifnames=0 biosdevname=0"@ /etc/default/grub 
root@ubuntu:~# cat /etc/default/grub |grep GRUB_CMDLINE_LINUX_DEFAULT
GRUB_CMDLINE_LINUX_DEFAULT="net.ifnames=0 biosdevname=0"
root@ubuntu:~# update-grub
Sourcing file `/etc/default/grub
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-4.15.0-55-generic
Found initrd image: /boot/initrd.img-4.15.0-55-generic
done

#2.
sed -ri /ens33/s@(.*)ens33:$@\\1eth0:@ /etc/netplan/01-netcfg.yaml 

#3.重启网卡
netplan apply

root@ubuntu:~# cat   /etc/netplan/01-netcfg.yaml
# This file describes the network interfaces available on your system
# For more information, see netplan(5).
network:
  version: 2
  renderer: networkd
  ethernets:
    eth0:
      dhcp4: no
      addresses: [192.168.47.54/24]
      gateway4: 192.168.47.2
      nameservers:
        addresses: [192.168.47.2]

​3.配置仓库​

​​https://developer.aliyun.com/mirror/ubuntu?spm=a2c6h.13651102.0.0.3e221b11imeuQV​​

​vim  /etc/apt/sources.list

ubuntu 18.04(bionic) 配置如下
-----------------------------------------------------------------------------------
deb http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse

deb http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse

deb http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse

deb http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse

deb http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse
-----------------------------------------------------------------------------------
apt-get  update  #升级仓库

​4.安装常用软件​

apt-get  install iproute2  ntpdate  tcpdump telnet traceroute nfs-kernel-server \\
nfs-common  lrzsz tree  openssl libssl-dev libpcre3 libpcre3-dev zlib1g-dev ntpdate \\
tcpdump telnet traceroute  gcc openssh-server lrzsz tree  openssl libssl-dev libpcre3 \\
libpcre3-dev zlib1g-dev ntpdate tcpdump telnet traceroute iotop unzip zip firewalld -y

​5.xshell连接ubuntu​

ps -e |grep ssh
sudo apt-get install openssh-server
sudo systemctl start sshd

​6.更改主机名​

root@ubuntu:~#  cat /etc/hostname 
ubuntu

​7.关闭防火墙​

systemctl stop firewalld
systemctl disable firewalld

​8.参数优化​

/etc/security/limits.conf

# /etc/security/limits.conf
#
#This file sets the resource limits for the users logged in via PAM.
#It does not affect resource limits of the system services.
#
#Also note that configuration files in /etc/security/limits.d directory,
#which are read in alphabetical order, override the settings in this
#file in case the domain is the same or more specific.
#That means for example that setting a limit for wildcard domain here
#can be overriden with a wildcard setting in a config file in the
#subdirectory, but a user specific setting here can be overriden only
#with a user specific setting in the subdirectory.
#
#Each line describes a limit for a user in the form:
#
#<domain>        <type>  <item>  <value>
#
#Where:
#<domain> can be:
#        - a user name
#        - a group name, with @group syntax
#        - the wildcard *, for default entry
#        - the wildcard %, can be also used with %group syntax,
#                 for maxlogin limit
#
#<type> can have the two values:
#        - "soft" for enforcing the soft limits
#        - "hard" for enforcing hard limits
#
#<item> can be one of the following:
#        - core - limits the core file size (KB)
#        - data - max data size (KB)
#        - fsize - maximum filesize (KB)
#        - memlock - max locked-in-memory address space (KB)
#        - nofile - max number of open file descriptors
#        - rss - max resident set size (KB)
#        - stack - max stack size (KB)
#        - cpu - max CPU time (MIN)
#        - nproc - max number of processes
#        - as - address space limit (KB)
#        - maxlogins - max number of logins for this user
#        - maxsyslogins - max number of logins on the system
#        - priority - the priority to run user process with
#        - locks - max number of file locks the user can hold
#        - sigpending - max number of pending signals
#        - msgqueue - max memory used by POSIX message queues (bytes)
#        - nice - max nice priority allowed to raise to values: [-20, 19]
#        - rtprio - max realtime priority
#
#<domain>      <type>  <item>         <value>
#

#*               soft    core            0
#*               hard    rss             10000
#@student        hard    nproc           20
#@faculty        soft    nproc           20
#@faculty        hard    nproc           50
#ftp             hard    nproc           0
#@student        -       maxlogins       4

# End of file

*                soft    core             unlimited
*                hard    core             unlimited
*              soft    nproc              1000000
*              hard    nproc             1000000
*              soft    nofile            1000000
*                hard    nofile          1000000
*                soft    memlock         32000
*                hard    memlock         32000
*                soft    msgqueue        8192000
*                hard    msgqueue        8192000

​/etc/sysctl.conf​

# Controls source route verification
net.ipv4.conf.default.rp_filter = 1
net.ipv4.ip_nonlocal_bind = 1
net.ipv4.ip_forward = 1

# Do not accept source routing
net.ipv4.conf.default.accept_source_route = 0

# Controls the System Request debugging functionality of the kernel
kernel.sysrq = 0

# Controls whether core dumps will append the PID to the core filename.
# Useful for debugging multi-threaded applications.
kernel.core_uses_pid = 1

# Controls the use of TCP syncookies
net.ipv4.tcp_syncookies = 1

# Disable netfilter on bridges.
net.bridge.bridge-nf-call-ip6tables = 0
net.bridge.bridge-nf-call-iptables = 0
net.bridge.bridge-nf-call-arptables = 0

# Controls the default maxmimum size of a mesage queue
kernel.msgmnb = 65536

# # Controls the maximum size of a message, in bytes
kernel.msgmax = 65536

# Controls the maximum shared segment size, in bytes
kernel.shmmax = 68719476736

# # Controls the maximum number of shared memory segments, in pages
kernel.shmall = 4294967296




# TCP kernel paramater
net.ipv4.tcp_mem = 786432 1048576 1572864
net.ipv4.tcp_rmem = 4096        87380   4194304
net.ipv4.tcp_wmem = 4096        16384   4194304
net.ipv4.tcp_window_scaling = 1
net.ipv4.tcp_sack = 1

# socket buffer
net.core.wmem_default = 8388608
net.core.rmem_default = 8388608
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.core.netdev_max_backlog = 262144
net.core.somaxconn = 20480
net.core.optmem_max = 81920


# TCP conn
net.ipv4.tcp_max_syn_backlog = 262144
net.ipv4.tcp_syn_retries = 3
net.ipv4.tcp_retries1 = 3
net.ipv4.tcp_retries2 = 15

# tcp conn reuse
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_fin_timeout = 1


net.ipv4.tcp_max_tw_buckets = 20000
net.ipv4.tcp_max_orphans = 3276800
net.ipv4.tcp_timestamps = 1 #?
net.ipv4.tcp_synack_retries = 1
net.ipv4.tcp_syncookies = 1

# keepalive conn
net.ipv4.tcp_keepalive_time = 300
net.ipv4.tcp_keepalive_intvl = 30
net.ipv4.tcp_keepalive_probes = 3
net.ipv4.ip_local_port_range = 10001    65000

# swap
vm.overcommit_memory = 0
vm.swappiness = 10

#net.ipv4.conf.eth1.rp_filter = 0
#net.ipv4.conf.lo.arp_ignore = 1
#net.ipv4.conf.lo.arp_announce = 2
#net.ipv4.conf.all.arp_ignore = 1
#net.ipv4.conf.all.arp_announce = 2