[oracle@localhost ~]$ ps -ef|grep smon
oracle 14809 1 0 Sep25 ? 00:13:02 ora_smon_mailp3
[oracle@localhost ~]$ export ORACLE_SID=mailp3
[oracle@localhost ~]$ echo $ORACLE_SID
mailp3
[oracle@localhost ~]$ sqlplus / as sysdba;
SQL*Plus: Release 11.2.0.3.0 Production on Thu Oct 19 10:07:36 2017
Copyright (c) 1982, 2011, Oracle. All rights reserved.
Connected to an idle instance.
SQL>
SQL> !env |grep ORACLE
ORACLE_SID=mailp3
ORACLE_BASE=/home/oracle
ORACLE_HOME=/home/oracle/product/11g
SQL> !cat /etc/oratab
#
# This file is used by ORACLE utilities. It is created by root.sh
# and updated by either Database Configuration Assistant while creating
# a database or ASM Configuration Assistant while creating ASM instance.
# A colon, ':', is used as the field terminator. A new line terminates
# the entry. Lines beginning with a pound sign, '#', are comments.
#
# Entries are of the form:
# $ORACLE_SID:$ORACLE_HOME:<N|Y>:
#
# The first and second fields are the system identifier and home
# directory of the database respectively. The third filed indicates
# to the dbstart utility that the database should , "Y", or should not,
# "N", be brought up at system boot time.
#
# Multiple entries with the same $ORACLE_SID are not allowed.
#
#
Ps eww 14809看启动进程的环境变量
[root@localhost bin]# ps eww 14809
PID TTY STAT TIME COMMAND
14809 ? Ss 13:02 ora_smon_mailp3 HOSTNAME=localhost.localdomain SHELL=/bin/bash TERM=vt100 HISTSIZE=1000 QTDIR=/usr/lib64/qt-3.3 QTINC=/usr/lib64/qt-3.3/include USER=oracle LS_COLORS=rs=0:di=01;34:ln=01;36:mh=00:pi=40;33:so=01;35:do=01;35:bd=40;33;01:cd=40;33;01:or=40;31;01:mi=01;05;37;41:su=37;41:sg=30;43:ca=30;41:tw=30;42:ow=34;42:st=37;44:ex=01;32:*.tar=01;31:*.tgz=01;31:*.arj=01;31:*.taz=01;31:*.lzh=01;31:*.lzma=01;31:*.tlz=01;31:*.txz=01;31:*.zip=01;31:*.z=01;31:*.Z=01;31:*.dz=01;31:*.gz=01;31:*.lz=01;31:*.xz=01;31:*.bz2=01;31:*.tbz=01;31:*.tbz2=01;31:*.bz=01;31:*.tz=01;31:*.deb=01;31:*.rpm=01;31:*.jar=01;31:*.rar=01;31:*.ace=01;31:*.zoo=01;31:*.cpio=01;31:*.7z=01;31:*.rz=01;31:*.jpg=01;35:*.jpeg=01;35:*.gif=01;35:*.bmp=01;35:*.pbm=01;35:*.pgm=01;35:*.ppm=01;35:*.tga=01;35:*.xbm=01;35:*.xpm=01;35:*.tif=01;35:*.tiff=01;35:*.png=01;35:*.svg=01;35:*.svgz=01;35:*.mng=01;35:*.pcx=01;35:*.mov=01;35:*.mpg=01;35:*.mpeg=01;35:*.m2v=01;35:*.mkv=01;35:*.ogm=01;35:*.mp4=01;35:*.m4v=01;35:*.mp4v=01;35:*.vob=01;35:*.qt=01;35:*.nuv=01;35:*.wmv=01;35:*.asf=01;35:*.rm=01;35:*.rmvb=01;35:*.flc=01;35:*.avi=01;35:*.fli=01;35:*.flv=01;35:*.gl=01;35:*.dl=01;35:*.xcf=01;35:*.xwd=01;35:*.yuv=01;35:*.cgm=01;35:*.emf=01;35:*.axv=01;35:*.anx=01;35:*.ogv=01;35:*.ogx=01;35:*.aac=01;36:*.au=01;36:*.flac=01;36:*.mid=01;36:*.midi=01;36:*.mka=01;36:*.mp3=01;36:*.mpc=01;36:*.ogg=01;36:*.ra=01;36:*.wav=01;36:*.axa=01;36:*.oga=01;36:*.spx=01;36:*.xspf=01;36: ORACLE_SID=mailp3 ORACLE_BASE=/home/oracle/ MAIL=/var/spool/mail/oracle PATH= PWD=/home/oracle LANG=en_US.UTF-8 SSH_ASKPASS=/usr/libexec/openssh/gnome-ssh-askpass HISTCONTROL=ignoredups SHLVL=1 HOME=/home/oracle LOGNAME=oracle QTLIB=/usr/lib64/qt-3.3/lib CVS_RSH=ssh LESSOPEN=|/usr/bin/lesspipe.sh %s ORACLE_HOME=/home/oracle//product/11g G_BROKEN_FILENAMES=1 _=/home/oracle//product/11g/bin/sqlplus ORA_NET2_DESC=9,12 ORACLE_SPAWNED_PROCESS=1 SKGP_SPAWN_DIAG_PRE_FORK_TS=1506332218 SKGP_SPAWN_DIAG_POST_FORK_T
发现
ORACLE_HOME=/home/oracle//product/11g
---->>两个/
把.bash_profile环境变量ORACLE_HOME=/home/oracle//product/11g改为这个问题解决