环境：oracle 11.2.0.3 RAC，linux ASM存储，数据库存储空间不够，添加ASM磁盘。整个过程不需要停集群以及数据库。
1、在磁盘上建分区
[root@RAC-1 mapper]# fdisk /dev/mapper/data15
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel with disk identifier 0x386ecaa5.
Changes will remain in memory only, until you decide to write them.
After that, of course, the previous content won't be recoverable.
Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)

WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
         switch off the mode (command 'c') and change display units to
         sectors (command 'u').

Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-26108, default 1): 1
Last cylinder, +cylinders or +size{K,M,G} (1-26108, default 26108): 
Using default value 26108




Command (m for help): w


2、加载已更新的块设备分区表（在rac的两台机器上执行）
/sbin/partprobe  /dev/mapper/data15
3、授权
chown -R oracle:oinstall  /dev/mapper/data15*
chmod -R 777 /dev/mapper/data15*


4、给磁盘组添加磁盘
su - grid
sqlplus  / as sysasm
alter diskgroup  data  add disk '/dev/mapper/data15p1';
su - grid
asmcmd
lsdg  ----可以看到磁盘组增加了200G。
5、添加完成后，进行数据库和集群检查，一切正常。