使用asmcmd时可能会遇到的一些问题，总结一下

C:>asmcmd
"asmcmd: the environment variable ORACLE_HOME is not set."

C:>set ORACLE_HOME='G:oracleproduct10.2.0db_1'
--进入asmcmd事先需要设置ORACLE_HOME环境变量一直是我所不能理解的，oracle为什么
要这么做，本来注册表里已经有了对ORACLE_HOME的设置，今天在讲课的时候一位学员
在设置ORACLE_HOME之后进入asmcmd时遇到了下面的错误：
C:>asmcmd
'perl.exe' 不是内部或外部命令，也不是可运行的程序
或批处理文件。
--仔细对比之后发现最后是由于在G:oracleproduct10.2.0db_1外面加了单引号
C:>set ORACLE_HOME=G:oracleproduct10.2.0db_1

C:>asmcmd
ORA-01034: ORACLE not available
ORA-27101: shared memory realm does not exist (DBD ERROR: OCISessionBegin)
C:>set oracle_sid=+asm

C:>asmcmd
ASMCMD> exit
--================================
通过修改sqlnet.ora里面的SQLNET.AUTHENTICATION_SERVICES= (none)屏蔽os认证
之后asmcmd进入时错误如下，最后通过asmcmd的help我们发现原来asmcmd其实隐含着登录
+asm的操作，需要os认证必须打开才能进入asmcmd。
--================================
C:>asmcmd
ORA-01031: insufficient privileges (DBD ERROR: OCISessionBegin)
C:>asmcmd
ASMCMD> help
asmcmd [-p] [command]

The environment variables ORACLE_HOME and ORACLE_SID determine the
instance to which the program connects, and ASMCMD establishes a
bequeath connection to it, in the same manner as a SQLPLUS / AS
SYSDBA. The user must be a member of the SYSDBA group.

Specifying the -p option allows the current directory to be displayed
in the command prompt, like so:

ASMCMD [+DATAFILE/ORCL/CONTROLFILE] >

[command] specifies one of the following commands, along with its
parameters.

Type "help [command]" to get help on a specific ASMCMD command.

commands:
--------
cd
du
find
help
ls
lsct
lsdg
mkalias
mkdir
pwd
rm
rmalias
ASMCMD>