是不是我的环境变量错了，su - root 不能运行。

zswlb9999

事实上所有root 权限的程序都不能运行,密码并没有问题。
bash-3.00$ su - root
Password:
su: incorrect password
bash-3.00$ set
BASH=/bin/bash
BASH_ARGC=()bash-3.00$ su - root
Password:
su: incorrect password
bash-3.00$ set
BASH=/bin/bash
BASH_ARGC=()
BASH_ARGV=()
BASH_LINENO=()
BASH_SOURCE=()
BASH_VERSINFO=([0]="3" [1]="00" [2]="15" [3]="1" [4]="release" [5]="i686-asianux-linux-gnu")
BASH_VERSION='3.00.15(1)-release'
COLORTERM=
COLUMNS=80
DBUS_SESSION_BUS_ADDRESS=unix:abstract=/tmp/dbus-Edy1DCVkff
DESKTOP_SESSION=default
DIRSTACK=()
DISPLAY=:0.0
EUID=500
GROUPS=()
GTK2_RC_FILES=/etc/gtk-2.0/gtkrc:/home/dgc/.gtkrc-2.0:/home/dgc/.kde/share/config/gtkrc
GTK_IM_MODULE=scim
GTK_RC_FILES=/etc/gtk/gtkrc:/home/dgc/.gtkrc:/home/dgc/.kde/share/config/gtkrc
G_BROKEN_FILENAMES=1
HISTFILE=/home/dgc/.bash_history
HISTFILESIZE=1000
HISTSIZE=1000
HOME=/home/dgc
HOSTNAME=localhost
HOSTTYPE=i686
IFS=$' \t\n'
INPUTRC=/etc/inputrc
JAVA_HOME=/usr/lib/jdk
KDE_FULL_SESSION=true
KDE_MULTIHEAD=false
KONSOLE_DCOP='DCOPRef(konsole-5216,konsole)'
KONSOLE_DCOP_SESSION='DCOPRef(konsole-5216,session-1)'
LANG=zh_CN.GB18030
LANGUAGE=zh_CN.GB18030:zh_CN.GB2312:zh_CN
LESSOPEN='|/usr/bin/lesspipe.sh %s'
LINES=24
LOGNAME=dgc
LS_COLORS=
MACHTYPE=i686-asianux-linux-gnu
MAIL=/var/spool/mail/dgc
MAILCHECK=60
OPTERR=1
OPTIND=1
OSTYPE=linux-gnu
PATH=/usr/lib/jdk/bin:/usr/kerberos/bin:/bin:/usr/bin:/usr/X11R6/bin:/usr/local/bin
PIPESTATUS=([0]="1")
PPID=5216
PS1='\s-\v\$ '
PS2='> '
PS4='+ '
PWD=/home/dgc
QTDIR=/usr/lib/qt-3.3
QT_IM_MODULE=scim
SESSION_MANAGER=local/localhost:/tmp/.ICE-unix/4708
SHELL=/bin/bash
SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
SHLVL=3
SSH_AGENT_PID=4645
SSH_ASKPASS=/usr/libexec/openssh/gnome-ssh-askpass
SSH_AUTH_SOCK=/tmp/ssh-hbHptH4644/agent.4644
TERM=xterm
UID=500
USER=dgc
WINDOWID=46137349
XCURSOR_SIZE=
XCURSOR_THEME=default
XDM_MANAGED=/var/run/xdmctl/xdmctl-:0,method=classic
XMODIFIERS=@im=SCIM
_=root
bash-3.00$
BASH_ARGV=()
BASH_LINENO=()
BASH_SOURCE=()
BASH_VERSINFO=([0]="3" [1]="00" [2]="15" [3]="1" [4]="release" [5]="i686-asianux-linux-gnu")
BASH_VERSION='3.00.15(1)-release'
COLORTERM=
COLUMNS=80
DBUS_SESSION_BUS_ADDRESS=unix:abstract=/tmp/dbus-Edy1DCVkff
DESKTOP_SESSION=default
DIRSTACK=()
DISPLAY=:0.0
EUID=500
GROUPS=()
GTK2_RC_FILES=/etc/gtk-2.0/gtkrc:/home/dgc/.gtkrc-2.0:/home/dgc/.kde/share/config/gtkrc
GTK_IM_MODULE=scim
GTK_RC_FILES=/etc/gtk/gtkrc:/home/dgc/.gtkrc:/home/dgc/.kde/share/config/gtkrc
G_BROKEN_FILENAMES=1
HISTFILE=/home/dgc/.bash_history
HISTFILESIZE=1000
HISTSIZE=1000
HOME=/home/dgc
HOSTNAME=localhost
HOSTTYPE=i686
IFS=$' \t\n'
INPUTRC=/etc/inputrc
JAVA_HOME=/usr/lib/jdk
KDE_FULL_SESSION=true
KDE_MULTIHEAD=false
KONSOLE_DCOP='DCOPRef(konsole-5216,konsole)'
KONSOLE_DCOP_SESSION='DCOPRef(konsole-5216,session-1)'
LANG=zh_CN.GB18030
LANGUAGE=zh_CN.GB18030:zh_CN.GB2312:zh_CN
LESSOPEN='|/usr/bin/lesspipe.sh %s'
LINES=24
LOGNAME=dgc
LS_COLORS=
MACHTYPE=i686-asianux-linux-gnu
MAIL=/var/spool/mail/dgc
MAILCHECK=60
OPTERR=1
OPTIND=1
OSTYPE=linux-gnu
PATH=/usr/lib/jdk/bin:/usr/kerberos/bin:/bin:/usr/bin:/usr/X11R6/bin:/usr/local/bin
PIPESTATUS=([0]="1")
PPID=5216
PS1='\s-\v\$ '
PS2='> '
PS4='+ '
PWD=/home/dgc
QTDIR=/usr/lib/qt-3.3
QT_IM_MODULE=scim
SESSION_MANAGER=local/localhost:/tmp/.ICE-unix/4708
SHELL=/bin/bash
SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
SHLVL=3
SSH_AGENT_PID=4645
SSH_ASKPASS=/usr/libexec/openssh/gnome-ssh-askpass
SSH_AUTH_SOCK=/tmp/ssh-hbHptH4644/agent.4644
TERM=xterm
UID=500
USER=dgc
WINDOWID=46137349
XCURSOR_SIZE=
XCURSOR_THEME=default
XDM_MANAGED=/var/run/xdmctl/xdmctl-:0,method=classic
XMODIFIERS=@im=SCIM
_=root
bash-3.00$

sunnyseckt

环境变量决定能否找到命令，应该和环境变量没关系。

会不会是文件系统（硬盘）的问题？我遇过一次有一台Linux的根文件系统dirty，很多命令df、du、vi都用不了，只好重启来解决。

bobkey

你的su是不是被替换了？贴出如下信息看看：

rpm -Vf `which su` (如果是Linux)
file `which su`
ldd `which su`
strings `which su`