[hadoop@localhost ~]$ visudo
visudo：/etc/sudoers：權限不夠
visudo：/etc/sudoers：權限不夠使用visudo命令打開sudo配置文件

## Sudoers allows particular users to run various commands as
## the root user, without needing the root password.
## 該文件允許特定用戶像root用戶一樣使用各種各樣的命令，而不需要root用戶的密碼
##
## Examples are provided at the bottom of the file for collections
## of related commands, which can then be delegated out to particular
## users or groups.
## 在文件的底部提供了很多相關命令的示例以供選擇，這些示例都可以被特定用戶或
## 用戶組所使用 
##
## This file must be edited with the 'visudo' command.
## 該文件必須使用"visudo"命令編輯

## Host Aliases
## Groups of machines. You may prefer to use hostnames (perhaps using 
## wildcards for entire domains) or IP addresses instead.
## 對于一組服務器，你可能會更喜歡使用主機名（可能是全域名的通配符）
## 、或IP地址，這時可以配置主機別名
# Host_Alias   FILESERVERS = fs1, fs2
# Host_Alias   MAILSERVERS = smtp, smtp2

## User Aliases
## These aren't often necessary, as you can use regular groups
## (ie, from files, LDAP, NIS, etc) in this file - just use %groupname 
## rather than USERALIAS
## 這并不很常用，因為你可以通過使用組來代替一組用戶的別名
# User_Alias ADMINS = jsmith, mikem

## Command Aliases
## These are groups of related commands...
## 指定一系列相互關聯(lián)的命令（當然可以是一個）的別名，通過賦予該別名sudo權限，
## 可以通過sudo調(diào)用所有別名包含的命令，下面是一些示例

## Networking 網(wǎng)絡操作相關命令別名
# Cmnd_Alias NETWORKING = /sbin/route, /sbin/ifconfig, /bin/ping, /sbin/dhclient
, /usr/bin/net, /sbin/iptables, /usr/bin/rfcomm, /usr/bin/wvdial, /sbin/iwconfig
, /sbin/mii-tool

## Installation and management of software 軟件安裝管理相關命令別名
# Cmnd_Alias SOFTWARE = /bin/rpm, /usr/bin/up2date, /usr/bin/yum

## Services 服務相關命令別名
# Cmnd_Alias SERVICES = /sbin/service, /sbin/chkconfig

## Updating the locate database 本地數(shù)據(jù)庫升級命令別名
# Cmnd_Alias LOCATE = /usr/bin/updatedb

## Storage 磁盤操作相關命令別名
# Cmnd_Alias STORAGE = /sbin/fdisk, /sbin/sfdisk, /sbin/parted, /sbin/partprobe
, /bin/mount, /bin/umount

## Delegating permissions 代理權限相關命令別名
# Cmnd_Alias DELEGATING = /usr/sbin/visudo, /bin/chown, /bin/chmod, /bin/chgrp

## Processes 進程相關命令別名
# Cmnd_Alias PROCESSES = /bin/nice, /bin/kill, /usr/bin/kill, /usr/bin/killall

## Drivers 驅(qū)動命令別名
# Cmnd_Alias DRIVERS = /sbin/modprobe

# Defaults specification

#
# Disable "ssh hostname sudo cmd>", because it will show the password in clear. 
#     You have to run "ssh -t hostname sudo cmd>".
# 一些環(huán)境變量的相關配置，具體情況可見man soduers
Defaults  requiretty

Defaults  env_reset
Defaults  env_keep = "COLORS DISPLAY HOSTNAME HISTSIZE INPUTRC KDEDIR LS_COLORS"
Defaults  env_keep += "MAIL PS1 PS2 QTDIR USERNAME LANG LC_ADDRESS LC_CTYPE"
Defaults  env_keep += "LC_COLLATE LC_IDENTIFICATION LC_MEASUREMENT LC_MESSAGES"
Defaults  env_keep += "LC_MONETARY LC_NAME LC_NUMERIC LC_PAPER LC_TELEPHONE"
Defaults  env_keep += "LC_TIME LC_ALL LANGUAGE LINGUAS _XKB_CHARSET XAUTHORITY"

Defaults  secure_path = /sbin:/bin:/usr/sbin:/usr/bin

## Next comes the main part: which users can run what software on 
## which machines (the sudoers file can be shared between multiple
## systems).
## 下面是規(guī)則配置：什么用戶在哪臺服務器上可以執(zhí)行哪些命令（sudoers文件可以在多個系統(tǒng)上共享）
## Syntax(語法):
##
## user MACHINE=COMMANDS 用戶 登錄的主機=（可以變換的身份） 可以執(zhí)行的命令
##
## The COMMANDS section may have other options added to it.
## 命令部分可以附帶一些其它的選項
##
## Allow root to run any commands anywhere 
## 允許root用戶執(zhí)行任意路徑下的任意命令
root ALL=(ALL) ALL

## Allows members of the 'sys' group to run networking, software, 
## service management apps and more.
## 允許sys中戶組中的用戶使用NETWORKING等所有別名中配置的命令
# %sys ALL = NETWORKING, SOFTWARE, SERVICES, STORAGE, DELEGATING, PROCESSES, LOCATE
, DRIVERS

## Allows people in group wheel to run all commands
## 允許wheel用戶組中的用戶執(zhí)行所有命令
%wheel ALL=(ALL) ALL

## Same thing without a password
## 允許wheel用戶組中的用戶在不輸入該用戶的密碼的情況下使用所有命令
# %wheel ALL=(ALL) NOPASSWD: ALL

## Allows members of the users group to mount and unmount the 
## cdrom as root
## 允許users用戶組中的用戶像root用戶一樣使用mount、unmount、chrom命令
# %users ALL=/sbin/mount /mnt/cdrom, /sbin/umount /mnt/cdrom

## Allows members of the users group to shutdown this system
## 允許users用戶組中的用戶關閉localhost這臺服務器
# %users localhost=/sbin/shutdown -h now

## Read drop-in files from /etc/sudoers.d (the # here does not mean a comment)
## 讀取放置在/etc/sudoers.d/文件夾中的文件（此處的#不意味著這是一個聲明）
#includedir /etc/sudoers.d