**一：查看磁盘组可用空间大小：** 1. [grid@rac1 ~]$ sqlplus / as sysasm //进入ASM实例 SQL> select name,allocation_unit_size,free_mb,total_mb from v$asm_diskgroup; NAME ALLOCATION_UNIT_SIZE FREE_MB TOTAL_MB ------------------------------ -------------------- ---------- ---------- OCR 1048576 29796 30722 DATA 1048576 58142 60256 2. [grid@rac1 ~]$ 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 EXTERN N 512 4096 1048576 60256 58142 0 58142 0 N DATA/ MOUNTED NORMAL N 512 4096 1048576 30722 29796 10241 9777 0 Y OCR/ **二：ASM磁盘组扩容（DATA扩容）** 事先准备好/dev/asm-disk5 **添加磁盘：** SQL> alter diskgroup DATA add disk '/dev/asm-disk5'; Diskgroup altered. 查看大小： SQL> select name,allocation_unit_size,free_mb,total_mb from v$asm_diskgroup; NAME ALLOCATION_UNIT_SIZE FREE_MB TOTAL_MB ------------ OCR 1048576 29796 30722 DATA 1048576 69052 71168 **删除磁盘：//需要磁盘在ASM中映射的名字 ** SQL> alter diskgroup DATA drop disk '/dev/asm-disk5'; alter diskgroup DATA drop disk '/dev/asm-disk5' * ERROR at line 1: ORA-15032: not all alterations performed ORA-15054: disk "/DEV/ASM-DISK5" does not exist in diskgroup "DATA" SQL> select name,path from v$asm_disk_stat; NAME PATH ------------------------------ ------------------------------ OCR_0000 /dev/asm-disk2 OCR_0002 /dev/asm-disk4 OCR_0001 /dev/asm-disk3 DATA_0000 /dev/asm-disk1 DATA_0001 /dev/asm-disk5 SQL> alter diskgroup data drop disk DATA_0001; Diskgroup altered. SQL> select name,allocation_unit_size,free_mb,total_mb from v$asm_diskgroup; NAME ALLOCATION_UNIT_SIZE FREE_MB TOTAL_MB ------------------------------ -------------------- ---------- ---------- OCR 1048576 29796 30722 DATA 1048576 58142 60256 由于ASM条带化特性，添加磁盘以及删除磁盘实际就是数据重新分布Rebalance的过程。