1、linux swap分区
可采用文件的方式
dd if=/dev/zero of=/var/swap bs=1024 count=2048000
mkswap /var/swap
swapon /var/swap
查看 free
记录到/etc/fstab
/var/swap swap swap defaults 0 0
关闭swap分区: swapoff /var/swap
2、samba挂载目录并共享于多台机器
比如挂载并共享 /opt/crawler目录
(1)vi /etc/samba/smb.conf
末尾添加
[weibo]
comment = weiboresult
path = /crawler/weibo
public = yes
writable = yes
printable = no
guest OK = yes
create mask = 777
directory mask = 777
(2)service smb restart
smbpasswd -a
输入:123456(密码)
(3)其他机器创建目录并设置文件共享:
mkdir -p /crawler/weibo
mount -t cifs //10.0.5.46/weibo /crawler/weibo -o username=root,password=123456
mount -t cifs //192.168.8.17/weibo /crawler/weibo -o username=root,password=123456
mount -t cifs //10.0.5.66/Images /crawler/weibo -o username=root,password=123456
mount -t cifs //192.168.1.103/weibo /crawler/weibo -o username=root,password=123456
3、安装nload(可查看机器带宽使用情况)
wget http://www.roland-riegel.de/nload/nload-0.7.2.tar.gz
tar -zxvf nload-0.7.2.tar.gz
cd nload-0.7.2
./configure
make && make install
1、-u设置屏显网卡带宽单位，子参数分别表示：b: Bit/s, k: kBit/s, m: MBit/s etc. B: Byte/s, K: kByte/s, M: MByte/s etc
nload -u m
2、 -t 设置屏显刷新时间，单位是毫秒，默认值是500
nload -t 80
需要安装gcc c++：yum install gcc-c++
可能出现的错误:
configure: error: ncurses library or development files not found. ncurses is required for nload.
解决:yum install -y ncurses-devel
4、查看Linux版本系统信息方法汇总
getconf LONG_BIT
lsb_release -a
cat /proc/cpuinfo | cat /etc/redhat-release
cat /etc/issue
cat /proc/cpuinfo| grep "processor"| wc -l
5、主机间进行信任
(1)方式一
缺省情况下，SSH将使用口令方式进行验证，不需要对系统进行任何配置，就可以使用账号和口令登录到远程服务器，也可以使用基于密钥认证的方式，下面是具体的配置步骤：( 两台服务器IP分别为192.168.1.1和192.168.1.2）
1、创建密钥
#ssh-keygen -d //加上参数 d是创建一个基于ssh2的密钥对
#Generating public/private rsa key pair.
#Enter file in which to save the key (/root/.ssh/id_rsa): [回车]
#Created directory '/root/.ssh'.
#Enter passphrase (empty for no passphrase): [回车]
#Enter same passphrase again: [回车]
Your identification has been saved in /root/.ssh/id_rsa.
Your public key has been saved in /root/.ssh/id_rsa.pub.
The key fingerprint is:
01:90:08:9e:7d:42:69:01:96:52:d7:ca:9f:53:43:df root@192.168.1.1
2、发布共钥到服务器上
将id_dsa.pub 发布到服务器上，更名为authorized_keys
#scp /root/.ssh/id_rsa.pub root@192.168.1.2:/root/.ssh/authorized_keys
root@192.168.20.150's password: [输入密码]
3、修改权限所有者
# chmod 644 /root/.ssh/authorized_keys
(2)方式二(改进)
在主信任机上:
1、/usr/bin/ssh-keygen -t rsa -N ""
敲两回车
2、cat /root/.ssh/id_rsa.pub | ssh 192.168.80.128 'cat >> .ssh/authorized_keys'
cat /root/.ssh/id_rsa.pub | ssh 192.168.80.129 'cat >> .ssh/authorized_keys'
cat /root/.ssh/id_rsa.pub | ssh 192.168.80.130 'cat >> .ssh/authorized_keys'
输入密码
6、查看机器上次重启
last reboot
who -b
uptime
7、查看机器出口IP
curl http://ip.3322.org
或者: curl http://1212.ip138.com/ic.asp
8、查看、统计网络连接情况
netstat -na|grep ESTABLISHED|wc -l 连接数
服务器的TCP状态(连接状态数量统计):
netstat -n | awk '/^tcp/ {++S[$NF]} END {for(a in S) print a, S[a]}'
9、查看端口占用情况
netstat -apn | grep 17786
注:17786为端口号
10、查看进程的状态(资源消耗等)
cat /proc/5741/status
其中5741为进程id
11、linux格式化windows上编写的脚本(.sh文件)
dos2unix *.sh
相应的也有unix2dos(linux转windows)、unix2mac(linux转mac)、mac2unix命令。
12、centos更换yum源
先进行备份：mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
1) 使用163 yum源：
CentOS7
wget http://mirrors.163.com/.help/CentOS7-Base-163.repo
CentOS6
wget http://mirrors.163.com/.help/CentOS6-Base-163.repo
CentOS5
wget http://mirrors.163.com/.help/CentOS5-Base-163.repo
运行yum makecache生成缓存：yum makecache
yum -y update
2) 使用aliyun yum源:
(1) 备份
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
(2) 下载新的CentOS-Base.repo 到/etc/yum.repos.d/
CentOS 5
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-5.repo
或者
curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-5.repo
CentOS 6
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-6.repo
或者
curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-6.repo
CentOS 7
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
或者
curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
(3)之后运行yum makecache生成缓存
13、Linux查看僵尸进程
ps -A -ostat,ppid,pid,cmd | grep -e '^[Zz]'
命令选项说明:
-A 参数列出所有进程
-o 自定义输出字段 我们设定显示字段为 stat（状态）, ppid（进程父id）, pid(进程id)，cmd（命令）这四个参数
因为状态为 z或者Z的进程为僵尸进程，所以我们使用grep抓取stat状态为zZ进程。
14、安装校时服务
yum -y install ntp
service ntp start
ntpdate asia.pool.ntp.org
chkconfig ntpd on