创建ASM磁盘组

https://docs.oracle.com/cd/B19306_01/server.102/b14200/statements_5008.htm

一、创建ASM磁盘组

SQL> show parameter asm_diskstring

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
asm_diskstring                       string      /dev/asm*

SQL> col name for a40
SQL> col value for a15
SQL> select group_number,name,value from v$asm_attribute where name in ('au_size','compatible.asm','compatible.rdbms');

GROUP_NUMBER NAME                                     VALUE
------------ ---------------------------------------- ---------------
           1 au_size                                  4194304
           1 compatible.asm                           11.2.0.0.0
           1 compatible.rdbms                         10.1.0.0.0

SQL> set linesize 200 pagesize 200
SQL> col path for a20
SQL> col name for a15
SQL> col failgroup for a15
SQL> select group_number,disk_number,failgroup,name,path,state,mount_status,total_mb,free_mb,os_mb from v$asm_disk;

GROUP_NUMBER DISK_NUMBER FAILGROUP       NAME            PATH                 STATE    MOUNT_S   TOTAL_MB    FREE_MB      OS_MB
------------ ----------- --------------- --------------- -------------------- -------- ------- ---------- ---------- ----------
           0           0                                 /dev/asm-diskg       NORMAL   CLOSED           0          0      10240
           0           1                                 /dev/asm-diskh       NORMAL   CLOSED           0          0      10240
           0           2                                 /dev/asm-diskf       NORMAL   CLOSED           0          0       4096
           0           3                                 /dev/asm-diske       NORMAL   CLOSED           0          0       4096
           1           2 OCRVOTING_0002  OCRVOTING_0002  /dev/asm-diskd       NORMAL   CACHED        1024        680       1024
           1           1 OCRVOTING_0001  OCRVOTING_0001  /dev/asm-diskc       NORMAL   CACHED        1024        676       1024
           1           0 OCRVOTING_0000  OCRVOTING_0000  /dev/asm-diskb       NORMAL   CACHED        1024        676       1024

7 rows selected.

SQL> create diskgroup FRA external redundancy
disk
'/dev/asm-diske' name FRA_0000,
'/dev/asm-diskf' name FRA_0001
attribute 'au_size'='4M',
'compatible.asm' = '11.2',
'compatible.rdbms' = '10.1';

Diskgroup created.

SQL> create diskgroup DATA external redundancy
disk
'/dev/asm-diskg' name DATA_0000,
'/dev/asm-diskh' name DATA_0001
attribute 'au_size'='4M',
'compatible.asm' = '11.2',
'compatible.rdbms' = '10.1';

Diskgroup created.

如果创建normal或high冗余磁盘组，则需要使用failgroup选项:
create diskgroup andy normal redundancy
failgroup fg1 disk
'/dev/asm-disko' name andy_fg1
failgroup fg2 disk
'/dev/asm-diskm' name andy_fg2
attribute 'au_size'='4M',
'compatible.asm' = '11.2',
'compatible.rdbms' = '11.1';

二、磁盘组参数

REDUNDANCY Clause

The REDUNDANCY clause lets you specify the redundancy level of the disk group.

• NORMAL REDUNDANCY requires the existence of at least two failure groups (see the FAILGROUP clause that follows). Automatic Storage Management provides redundancy for all files in the disk group according to the attributes specified in the disk group templates. NORMAL REDUNDANCY disk groups can tolerate the loss of one group. Please refer to ALTER DISKGROUP ... diskgroup_template_clauses for more information on disk group templates.
• HIGH REDUNDANCY requires the existence of at least three failure groups. Automatic Storage Management fixes mirroring at 3-way mirroring, with each extent getting two mirrored copies. HIGH REDUNDANCY disk groups can tolerate the loss of two failure groups.
• EXTERNAL REDUNDANCY indicates that Automatic Storage Management does not provide any redundancy for the disk group. The disks within the disk group must provide redundancy (for example, using a storage array), or you must be willing to tolerate loss of the disk group if a disk fails (for example, in a test environment). You cannot specify the FAILGROUP clause if you specify EXTERNAL REDUNDANCY.

FAILGROUP Clause

Use this clause to specify a name for one or more failure groups. If you omit this clause, and you have specified NORMAL or HIGH REDUNDANCY, then Oracle Database automatically adds each disk in the disk group to its own failure group. The implicit name of the failure group is the same as the operating system independent disk name (see "NAME Clause").

You cannot specify this clause if you are creating an EXTERNAL REDUNDANCY disk group.

关于asm_diskstring参数：

定义哪些磁盘可以被ASM使用。ASM实例启动之后，就根据这个参数扫描发现ASM磁盘，配置了这个参数以后，还必须要确认oracle用户对这些磁盘有操作权限。

• 如果使用的是裸设备，用逗号分隔每个设备名

asm_diskstring='/dev/raw/raw3','/dev/raw/raw7'

• 也可以使用通配符

asm_diskstring='/dev/raw/raw*'

• 使用ASMLib时，需要使用“ORCL:磁盘名”格式

asm_diskstring='ORCL:KEL1'

• 也可以使用通配符

asm_diskstring='ORCL:KEL*'