1.安装中文语言包及切换
yum groupinstall chinese-support
vi /etc/sysconfig/i18n change en_US to zh_CN
2.用户自动登录
vi /etc/gdm/custom.conf
[daemon] AutomaticLogin=root
AutomaticLoginEnable=true
TimedLoginEnable=true
TimedLogin=root
TimedLoginDelay=
3.RHEL 更改yum更新源为centos
、删除redhat原有的yum源 # rpm -aq | grep yum|xargs rpm -e --nodeps
、下载新的yum安装包 这里我们使用CentOS的yum源 #wget http://mirror.centos.org/centos/6/os/x86_64/Packages/python-iniparse-0.3.1-2.1.el6.noarch.rpm #wget http://mirror.centos.org/centos/6/os/x86_64/Packages/yum-metadata-parser-1.1.2-16.el6.x86_64.rpm # wget http://mirror.centos.org/centos/6/os/x86_64/Packages/yum-3.2.29-40.el6.centos.noarch.rpm #wget http://mirror.centos.org/centos/6/os/x86_64/Packages/yum-plugin-fastestmirror-1.1.30-14.el6.noarch.rpm 、安装yum软件包 [root@localhost 桌面]# rpm -ivh python-iniparse-0.3.-2.1.el6.noarch.rpm
warning: python-iniparse-0.3.-2.1.el6.noarch.rpm: Header V3 RSA/SHA256 Signature, key ID c105b9de: NOKEY
Preparing... ########################################### [%]
package python-iniparse-0.3.-2.1.el6.noarch is already installed
[root@localhost 桌面]# rpm -ivh yum-metadata-parser-1.1.-.el6.x86_64.rpm
warning: yum-metadata-parser-1.1.-.el6.x86_64.rpm: Header V3 RSA/SHA1 Signature, key ID c105b9de: NOKEY
Preparing... ########################################### [%]
:yum-metadata-parser ########################################### [%]
[root@localhost 桌面]# rpm -ivh yum-3.2.-.el6.centos.noarch.rpm yum-plugin-fastestmirror-1.1.-.el6.noarch.rpm
warning: yum-3.2.-.el6.centos.noarch.rpm: Header V3 RSA/SHA1 Signature, key ID c105b9de: NOKEY
Preparing... ########################################### [%]
:yum-plugin-fastestmirro########################################### [ %]
:yum ########################################### [%]
[root@localhost 桌面]# yum update
Loaded plugins: fastestmirror
Setting up Update Process
No Packages marked for Update 注意：最后两个安装包要放在一起同时安装，否则会提示相互依赖，安装失败。
4. CENTOS 6.4 安装后出现virt-who启动失败，提示没有rhsm.connection.
安装python-rhsm包和python-simplejson包
python-rhsm 可以在http://rpm.pbone.net/index.php3/stat/4/idpl/19915375/dir/scientific_linux_5/com/python-rhsm-1.0.10-1.el5.x86_64.rpm.html 下载编译安装
python-simplejson可以用yum安装。
本地下载python-rhsm
http://files.cnblogs.com/biangbiang/python-rhsm-1.0.10.zip
5.为centos增加rpmforce源地址
RPMForce 包含一些其它的有用工具包，如我喜欢用的多窗口终端 terminator:
wget http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.2-2.el6.rf.x86_64.rpm rpm --import http://apt.sw.be/RPM-GPG-KEY.dag.txt rpm -K rpmforge-release-0.5.-.el6.rf.x86_64.rpm rpm -i rpmforge-release-0.5.-.el6.rf.x86_64.rpm yum install terminator
6. fdisk 查看分区时遇到“Partition 1 does not end on cylinder boundary”警告
Device Boot Start End Blocks Id System
/dev/sda1 * Linux
Partition does not end on cylinder boundary.
/dev/sda2 Linux
Partition does not end on cylinder boundary.
/dev/sda3 + 8e Linux LVM
This was a bit disconcerting at first, but after a few minutes of thinking it dawned on me that modern systems use LBA (Logical Block Addressing) instead of CHS (Cylinder/Head/Sector) to address disk drives. If we view the partition table using sectors instead of cylinders:
刚开始很让人困惑,但是几分钟之后,我意识到现代操作系统使用LBA而不是CHS来记录硬盘分区.如果用扇区代替柱面,我们将看到:
sfdisk -uS -l /dev/sda
复制代码
Disk /dev/sda: cylinders, heads, sectors/track
Units = sectors of bytes, counting from Device Boot Start End #sectors Id System
/dev/sda1 * Linux
/dev/sda2 Linux
/dev/sda3 8e Linux LVM
/dev/sda4 - Empty
We can see that we end at a specific sector number, and start the next partition at that number plus one. I must say that I have grown quite fond of sfdisk and parted, and they sure make digging through DOS and GPT labels super easy.
我们可以看到,扇区是结束在一个特定的扇区,并且下一个分区的起始扇区在前一个的后面+1扇区.
7. 扩展root分区。
fdisk -l
fdisk /dev/sda
... 增加物理硬盘并分区，假设新增的分区为/dev/sda3 pvs
pvcreate /dev/sda3
vgs
vgextend VolGroup /dev/sda3
lvs
lvextend /dev/VolGroup/lv_root /dev/sda3 resize2fs /dev/VolGroup/lv_root df -h
8. Too many authentication failures for root :
#临时办法
ssh -o PubkeyAuthentication=no [email protected] #根本原因是使用ssh key互信的机器数超过了限制
vi /etc/ssh/sshd_config
MaxAuthTries 20 (默认是6)
还有其它更安全的办法，参考：
http://www.lamolabs.org/blog/6259/one-liner-working-around-the-ssh-error-message-too-many-authentication-failures-for-root/
9. 常用命令
删除0字节文件
find -type f -size -exec rm -rf {} \; 查看进程，按内存从大到小排列
ps -e -o "%C : %p : %z : %a"|sort -k5 -nr 按cpu利用率从大到小排列
ps -e -o "%C : %p : %z : %a"|sort -nr 查看http的并发请求数及其TCP连接状态：
netstat -n | awk '/^tcp/ {++S[$NF]} END {for(a in S) print a, S[a]}' 如何杀掉mysql进程：
ps aux |grep mysql |grep -v grep |awk'{print $2}' |xargs kill - 显示运行3级别开启的服务:
ls /etc/rc3.d/S* |cut -c - 取IP地址：
ifconfig eth0 |grep "inet addr:" |awk '{print $2}'|cut -c - 或者
ifconfig | grep 'inet addr:'| grep -v '127.0.0.1' | cut -d: -f2 | awk '{ print$1}' 内存的大小:
free -m |grep "Mem" | awk '{print $2}' 统计一下服务器下面所有的jpg的文件的大小
find / -name *.jpg -exec wc -c {} \;|awk '{print $1}'|awk '{a+=$1}END{print a}' 统计代码行数：
find nova/ -name "*.py" | xargs wc -l 占用空间最多的文件或目录：
# du -cks * | sort -rn | head -n 进程总数
ps aux | wc -l 打开文件数目
lsof | wc -l 清除僵死进程。
ps -eal | awk '{ if ($2 == "Z") {print $4}}' | kill - 匹配中文字符的正则表达式： [\u4e00-\u9fa5]
匹配空白行的正则表达式：\n\s*\r
匹配首尾空白字符的正则表达式：^\s*|\s*$
匹配Email地址的正则表达式：\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*
匹配网址URL的正则表达式：[a-zA-z]+://[^\s]*
匹配ip地址：\d+\.\d+\.\d+\.\d+ 重复执行命令：
watch -n -d 'netstat -nat | grep 9696 -c'
watch -n -d "mysql -uroot -pGalax8800 -e 'show processlist;' | grep quantum | wc -l"
9.NFS mount chown 不管，按指定用户mount
mount -t nfs -o vers= 10.10.10.10:/nfshome /localhome