ASM实例目前无论是在rac还是单实例数据库环境下都被广泛的采用，本文主要介绍Oracle 11.2.0.3环境下ASM实例的管理，主要包含以下内容：
1：ASM磁盘及磁盘组的状态查看
2：创建external 冗余磁盘组,添加，删除磁盘
3：创建normal redundancy磁盘组
4：normal redundancy下的failgroup测试
5：删除ASM磁盘组
6：其他asm实例初始化参数含义
一：查看ASM磁盘及磁盘组状态
SQL> select * from v$asm_disk;
SQL> select * from v$asm_diskgroup;
二：创建external 冗余磁盘组,添加，删除磁盘，删除磁盘的时候需要指定磁盘的name而不是path
- SQL> create diskgroup FRA external redundancy disk '/dev/asm-disk4';
- Diskgroup created.
- SQL> alter diskgroup fra add disk '/dev/asm-disk5' rebalance power 10;
- Diskgroup altered.
- SQL> select name,failgroup,path from v$asm_disk;
- NAME FAILGROUP PATH
- -------------------- -------------------- --------------------
- DATA_0000 DATA_0000 /dev/asm-disk1
- DATA_0001 DATA_0001 /dev/asm-disk3
- DATA_0002 DATA_0002 /dev/asm-disk2
- FRA_0000 FRA_0000 /dev/asm-disk4
- FRA_0001 FRA_0001 /dev/asm-disk5
- /dev/asm-disk6
- /dev/asm-disk7
- SQL> alter diskgroup fra drop disk '/dev/asm-disk4' rebalance power 10;
- alter diskgroup fra drop disk '/dev/asm-disk4' rebalance power 10
- *
- ERROR at line 1:
- ORA-15032: not all alterations performed
- ORA-15054: disk "/DEV/ASM-DISK4" does not exist in diskgroup "FRA"
- SQL> alter diskgroup fra drop disk 'FRA_0000' rebalance power 10;
- Diskgroup altered.
三：创建normal redundancy磁盘组
- SQL> conn /as sysasm
- Connected.
- SQL> create diskgroup fra normal redundancy
- failgroup fg1 disk '/dev/asm-disk4','/dev/asm-disk5'
- failgroup fg2 disk '/dev/asm-disk6','/dev/asm-disk7'
- attribute 'compatible.rdbms'='11.2','compatible.asm'='11.2';
- Diskgroup created.
- SQL> select name, total_mb,free_mb,required_mirror_free_mb,usable_file_mb from v$asm_diskgroup;
- NAME TOTAL_MB FREE_MB REQUIRED_MIRROR_FREE_MB USABLE_FILE_MB
- ---------- ---------- ---------- ----------------------- --------------
- DATA 61440 54873 0 18291
- FRA 81920 81592 20480 30556
四：failgroup测试；FAILGROUP是用于将磁盘分组，以保证丢失任何一组FAILGROUP磁盘，数据还是完整的,多用于多阵列，通过ASM来完成冗余的环境！
1：查看FRA磁盘组中failgroup信息及磁盘状态
- SQL> select name,path,failgroup,mount_status from v$asm_disk where group_number=2;
- NAME PATH FAILGROUP MOUNT_STATUS
- -------------------- -------------------- ---------- ---------------------
- FRA_0003 /dev/asm-disk7 FG2 CACHED
- FRA_0002 /dev/asm-disk6 FG2 CACHED
- FRA_0000 /dev/asm-disk4 FG1 CACHED
- FRA_0001 /dev/asm-disk5 FG1 CACHED
2：在rdbms实例中创建表空间，建表并插入数据，收集表统计信息
- SQL> create tablespace test01 datafile '+FRA';
- Tablespace created.
- ASMCMD> pwd
- +fra/db/datafile
- ASMCMD> ls
- TEST01.256.800622493
- SQL> create table t1 tablespace test01 as select * from dba_objects;
- Table created.
- SQL> exec dbms_stats.gather_table_stats('SYS','T1');
- PL/SQL procedure successfully completed.
- SQL> select count(*) from t1;
- COUNT(*)
- ----------
- 74501
3：删除udev相关规则，重启数据库实例和ASM实例，验证数据是否存在
- SQL> conn /as sysasm
- Connected.
- SQL> alter diskgroup fra mount;
- alter diskgroup fra mount
- *
- ERROR at line 1:
- ORA-15032: not all alterations performed
- ORA-15040: diskgroup is incomplete
- ORA-15042: ASM disk "1" is missing from group number "2"
- ORA-15042: ASM disk "0" is missing from group number "2"
- SQL> alter diskgroup fra mount force;
- Diskgroup altered.
- SQL> select name,path,failgroup,mount_status from v$asm_disk;
- NAME PATH FAILGROUP MOUNT_STATUS
- ---------- -------------------- -------------------- ---------------------
- FRA_0000 FG1 MISSING
- FRA_0001 FG1 MISSING
- FRA_0002 /dev/asm-disk6 FG2 CACHED
- FRA_0003 /dev/asm-disk7 FG2 CACHED
- DATA_0000 /dev/asm-disk1 DATA_0000 CACHED
- DATA_0002 /dev/asm-disk2 DATA_0002 CACHED
- DATA_0001 /dev/asm-disk3 DATA_0001 CACHED
- 7 rows selected.
- SQL> conn /as sysdba
- Connected.
- SQL> select count(*) from t1;
- COUNT(*)
- ----------
- 74501
五：删除ASM磁盘组，默认磁盘故障条件下，经过12960秒即3.6个小时后自动删除；删除磁盘组之前需要保证无数据存放在磁盘组上且无到该磁盘组的active连接
- [grid@localhost ~]$ tail -f /u01/app/grid/diag/asm/+asm/+ASM/trace/alert_+ASM.log
- ORA-15062: ASM disk is globally closed
- Thu Nov 29 12:00:53 2012
- WARNING: Disk 0 (FRA_0000) in group 2 will be dropped in: (12960) secs on ASM inst 1
- WARNING: Disk 1 (FRA_0001) in group 2 will be dropped in: (12960) secs on ASM inst 1
- Thu Nov 29 12:00:58 2012
- asm实例：
- SQL> select path,name,repair_timer from v$asm_disk where group_number=2;
- PATH NAME REPAIR_TIMER
- -------------------- ---------- ------------
- FRA_0000 12960
- FRA_0001 12960
- /dev/asm-disk6 FRA_0002 0
- /dev/asm-disk7 FRA_0003 0
- SQL> alter diskgroup fra online disk 'FRA_0000';
- Diskgroup altered.
- SQL> alter diskgroup fra online disk 'FRA_0001';
- Diskgroup altered.
- SQL> select name,path,failgroup,mount_status from v$asm_disk;
- NAME PATH FAILGROUP MOUNT_STATUS
- ---------- -------------------- -------------------- ---------------------
- FRA_0002 /dev/asm-disk6 FG2 CACHED
- FRA_0003 /dev/asm-disk7 FG2 CACHED
- DATA_0000 /dev/asm-disk1 DATA_0000 CACHED
- DATA_0002 /dev/asm-disk2 DATA_0002 CACHED
- DATA_0001 /dev/asm-disk3 DATA_0001 CACHED
- FRA_0001 /dev/asm-disk5 FG1 CACHED
- FRA_0000 /dev/asm-disk4 FG1 CACHED
- SQL> drop diskgroup fra;
- drop diskgroup fra
- *
- ERROR at line 1:
- ORA-15039: diskgroup not dropped
- ORA-15053: diskgroup "FRA" contains existing files
- rdbms实例：
- SQL> drop tablespace test01 including contents;
- Tablespace dropped.
- SQL> shutdown immediate
- Database closed.
- Database dismounted.
- ORACLE instance shut down.
- asm实例：
- SQL> drop diskgroup fra including contents;
- Diskgroup dropped.
- rdbms实例：
- SQL> startup
- ORACLE instance started.
- Total System Global Area 313860096 bytes
- Fixed Size 1344652 bytes
- Variable Size 192940916 bytes
- Database Buffers 113246208 bytes
- Redo Buffers 6328320 bytes
- Database mounted.
- Database opened.
六：其他asm实例初始化参数含义
| instance_type：Defines the type of the instance, such as RDBMS and ASM. However, this has been made optional in an Oracle Grid Infrastructure ASM. asm_power_limit：Manages the degree of parallelism to speed up the ASM disk rebalance operations, for example, whenever a disk is being dropped from an existing disk group or when the disk group rebalance is initiated manually. This is a dynamic parameter that can be set in the range from 0 to 11 (1024 in 11gR2 and above). Considering the size of a disk group, you may increase the limit of the POWER to speed up the rebalancing operation. Multiple ASM instances can hold the different values across a cluster. When no limit is specified, it uses the default value for the rebalancing operation. asm_diskstring: Used by the ASM instance to identify and discover the disks mentioned in the paths. Once the disks are discovered, they will appear in the V$ASM_DISK dynamic view. The disk discovery occurs when an ASM instance is initiated, when you issue a query against the V$ASM_DISK/V$ASM_DISKGROUP dynamic views, or when you MOUNT, UNMOUNT, RESIZE, ADD a disk. It is a dynamic parameter and you can specify multiple paths within this parameter processes: Apart from the SGA initialization parameter value, the PROCESSES initialization parameter value has some influence over the ASM instance. Therefore, you may use the following formula to tune the PROCESSES initialization parameter when multiple database instances are accessing the instance: 本文转自斩月博客51CTO博客，原文链接http://blog.51cto.com/ylw6006/1074053如需转载请自行联系原作者 ylw6006 |
