Linux system post-installation optimization

1. add a regular user, bysudoAuthorization Management

add a regular user, by sudo Authorization Management

2. add a regular user, bysudoAuthorization Management

Port 52113

Usedns No

Permitrootlogin No

Permitemptypasswords No

gssapiauthentication N o

3. NTPConfiguration(Time Synchronization)

/usr/sbin/ntpdate time.nist.gov

Echo ' */5 * * * * */usr/sbin/ntpdate time.nist.gov ' &>/dev/null

4. Character Set

[Email protected] ~]# cat/etc/sysconfig/i18n

Lang= "ZH_CN. UTF-8 "

[Email protected] ~]# ^c

[Email protected] ~]# echo $LANG

En

[Email protected] ~]#

5. enlarge file Descriptor

Adjust the number of file descriptors, and the process and file opening will consume the file descriptor

View Ulimi T –n

Temporary Increase Ulimi T -HSN 65535

Permanent Configuration /etc/security/limits.conf

echo "*-Nofile 65535" >>/etc/security/limits.conf

Log off and log back in

on request If a large number of concurrent recommendations are turned off, the front end uses a hardware firewall

6, firewall optimization (a large number of concurrent Web sites are not recommended to open the firewall, should use a hardware firewall)

Firewall optimization

Net.nf_conntrack_max = 25000000

Net.netfilter.nf_conntrack_max = 25000000

net.netfilter.nf_conntrack_tcp_timeout_established = 180

net.netfilter.nf_conntrack_tcp_timeout_time_wait = 120

Net.netfilter.nf_conntrack_tcp_timeout_colse_wait = 60

net.netfilter.nf_conntrack_tcp_timeout_fin_wait = 120

7. SELinux

Close vim/etc/selinux/config selinux=disabled

8. Kernel optimization

configuration file /etc/sysctl.conf

Refresh sysctl-p

Net.ipv4.tcp_fin_timeout = 2

Net.ipv4.tcp_tw_reuse = 1

Net.ipv4.tcp_tw_recycle = 1

Net.ipv4.tcp_syncookies = 1

Net.ipv4.tcp_keepalived_time = 600

Net.ipv4.ip_local_port_range = 4000 65000

Net.ipv4.tcp_max_syn_backlog = 16384

Net.ipv4.tcp_max_tw_buckets = 36000

Net.ipv4.route.gz_timeout = 100

Net.ipv4.tcp_syn_retries = 1

Net.core.somaxconn = 16384

Net.core.netdev_max_backlog = 16384

Net.ipv4.tcp_max_orphans = 16384

9, hide the system version also version number

vim/etc/issue Modify a file

>/etc/issue Clear

echo "" >/etc/redhat.release

Modify the warning message.

Vim/etc/motd

Lock File system security files

Chattr +i/etc/passwd/etc/shadow/etc/group/etc/gshadow/etc/inittab

lsattr/etc/passwd View file Properties

Modify chattr the name of the command

Mv/usr/bin/charttr/usr/bin/lock ( You can remember )

This article is from the "Fire Fist Ace" blog, please be sure to keep this source http://xinzong.blog.51cto.com/10018904/1693399

Linux system post-installation optimization