aix7.1 + 双节点oracle rac 11.2.0.3，由于此套rac并非自己部门安装，是开发部安装，现交由运维部分来管理，客户需要要将asm di
交代环境：
aix7.1 + 双节点oracle rac 11.2.0.3
由于此套rac并非自己部门安装，是开发部安装，现交由运维部分来管理，客户需要要将asm  diskgroup name 安装部门规范来命令。遂需要将oasmdgdata1更改为datadg。
幸好oracle的版本是11gr2，在11gr2中，oracle有一项新特性，可以直接使用renamedg命令更改diskgroup的名称。
下面是具体的操作步骤。
grid@sundb01:/home/grid>asmcmd
asmcmd> lsdg
state    type    rebal  sector  block      au  total_mb  free_mb  req_mir_free_mb  usable_file_mb  offline_disks  voting_files  name
mounted  normal  n        512  4096  1048576    358400  358192                0          179096              0            n  oasmdgdata01/
mounted  normal  n        512  4096  1048576    15360    14434            5120            4657              0            y  ocrdg/
asmcmd> umount oasmdgdata01
asmcmd> lsdg
state    type    rebal  sector  block      au  total_mb  free_mb  req_mir_free_mb  usable_file_mb  offline_disks  voting_files  name
mounted  normal  n        512  4096  1048576    15360    14434            5120            4657              0            y  ocrdg/
grid@sundb01:/home/grid>renamedg -help
note: no asm libraries found in the system
parsing parameters..
phase                          phase to execute,
                                (phase=one|two|both), default both
dgname                          diskgroup to be renamed
newdgname                      new name for the diskgroup
config                          intermediate config file
check                          just check-do not perform actual operation,
                                (check=true/false), default false
confirm                        confirm before committing changes to disks,
                                (confirm=true/false), default false
clean                          ignore errors,
                                (clean=true/false), default true
asm_diskstring                  asm diskstring (asm_diskstring='discoverystring',
                                'discoverystring1' ...)
verbose                        verbose execution,
                                (verbose=true|false), default false
keep_voting_files              voting file attribute,
                                (keep_voting_files=true|false), default false
利用renamedg来更改diskgroup的名称：
grid@sundb01:/home/grid>renamedg phase=both dgname=oasmdgdata01 newdgname=datadg verbose=true
note: no asm libraries found in the system
parsing parameters..
parameters in effect:
old dg name      : oasmdgdata01
        new dg name          : datadg
        phases              :
                phase 1
                phase 2
        discovery str        : 
        clean              : true
        raw only          : true
renamedg operation: phase=both dgname=oasmdgdata01 newdgname=datadg verbose=true
executing phase 1
discovering the group
performing discovery with string:
identified disk ufs:/dev/rhdisk2 with disk number:1 and timestamp (33002374 -296274944)
identified disk ufs:/dev/rhdisk1 with disk number:0 and timestamp (33002374 -296274944)
checking for hearbeat...
re-discovering the group
performing discovery with string:
identified disk ufs:/dev/rhdisk2 with disk number:1 and timestamp (33002374 -296274944)
identified disk ufs:/dev/rhdisk1 with disk number:0 and timestamp (33002374 -296274944)
checking if the diskgroup is mounted or used by css
checking disk number:1
checking disk number:0
generating configuration file..
completed phase 1
executing phase 2
looking for /dev/rhdisk2
modifying the header
looking for /dev/rhdisk1
modifying the header
completed phase 2
terminating kgfd context 110285ba0
grid@sundb01:/home/grid>
grid@sundb01:/home/grid>sqlplus / as sysasm
sql*plus: release 11.2.0.3.0 production on fri oct 10 12:33:31 2014
copyright (c) 1982, 2011, oracle.  all rights reserved.
connected to:
oracle database 11g enterprise edition release 11.2.0.3.0 - 64bit production
with the real application clusters and automatic storage management options
sql> select name,state from v$asm_diskgroup;