linux

root@SA-ubuntu-server:~# cat /etc/sudoers
#
# This file MUST be edited with the 'visudo' command as root.
#
# Please consider adding local content in /etc/sudoers.d/ instead of
# directly modifying this file.
#
# See the man page for details on how to write a sudoers file.
#
Defaults env_reset
Defaults mail_badpass
Defaults secure_path="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"

# Host alias specification

# User alias specification

# Cmnd alias specification

# User privilege specification
root ALL=(ALL:ALL) ALL

# Members of the admin group may gain root privileges
%admin ALL=(ALL) ALL

# Allow members of group sudo to execute any command
%sudo ALL=(ALL:ALL) ALL

theuser ALL=(ALL:ALL) NOPASSWD:ALL
# See sudoers(5) for more information on "#include" directives:

#includedir /etc/sudoers.d

 

idealsa@SA-ubuntu-server:~$ id theuser
uid=1000(theuser) gid=1000(theuser) groups=1000(theuser),4(adm),24(cdrom),27(sudo),30(dip),46(plugdev),110(lpadmin),111(sambashare)

　　

 

 

tcp连接优化

cat /etc/sysctl.conf

net.nf_conntrack_max = 655360
net.netfilter.nf_conntrack_tcp_timeout_established = 432000
net.ipv4.tcp_tw_reuse=1
net.ipv4.tcp_tw_recycle=0
net.ipv4.tcp_fin_timeout=30
vm.overcommit_memory = 1

sysctl -p

备注：

tcp_tw_reuse置为1，可以使连接复用

tcp_tw_recycle置为1，可以加速回收



vi /etc/security/limits.conf

* soft nproc 65535
* hard nproc 65535
root soft nofile 65535
root hard nofile 65535

备注：ubuntu系统如果是优化root用户的文件打开数量，一定要写root, 而不能使用 ‘*’ （星号）, 否则会发现ulimit -a没有生效