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How to Rearrange Failure Group According To Their Physical Locations

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By default, each disk has its own failure group if you did not assign failure groups while creating diskgroup. Since there is no failure group configuration syntax in "ALTER DISKGROUP ..." statement. You can only rearrange the disks into different failure groups by dropping and adding disks. Here is a demonstration to rearrange failure groups:

Check current status before rearrangement.
[oracle@primary01 ~]$ sqlplus / as sysasm
...
SQL> column diskgroup format a10;
SQL> column disk_name format a10;
SQL> column failgroup format a10;
SQL> column path format a12;
SQL> select dg.name diskgroup, dk.path, dk.name disk_name, dk.failgroup, dk.mount_status, dk.mode_status from v$asm_disk dk, v$asm_diskgroup dg where dk.group_number = dg.group_number;

DISKGROUP  PATH         DISK_NAME  FAILGROUP  MOUNT_S MODE_ST
---------- ------------ ---------- ---------- ------- -------
DATA       ORCL:DISK01  DISK01     DISK01     CACHED  ONLINE
DATA       ORCL:DISK02  DISK02     DISK02     CACHED  ONLINE
DATA       ORCL:DISK03  DISK03     DISK03     CACHED  ONLINE
DATA       ORCL:DISK04  DISK04     DISK04     CACHED  ONLINE
DATA       ORCL:DISK05  DISK05     DISK05     CACHED  ONLINE
DATA       ORCL:DISK06  DISK06     DISK06     CACHED  ONLINE
DATA       ORCL:DISK07  DISK07     DISK07     CACHED  ONLINE
DATA       ORCL:DISK08  DISK08     DISK08     CACHED  ONLINE

8 rows selected.

SQL> select name disk_name, path, mount_status, mode_status, state from v$asm_disk;

DISK_NAME  PATH         MOUNT_S MODE_ST STATE
---------- ------------ ------- ------- --------
DISK01     ORCL:DISK01  CACHED  ONLINE  NORMAL
DISK02     ORCL:DISK02  CACHED  ONLINE  NORMAL
DISK03     ORCL:DISK03  CACHED  ONLINE  NORMAL
DISK04     ORCL:DISK04  CACHED  ONLINE  NORMAL
DISK05     ORCL:DISK05  CACHED  ONLINE  NORMAL
DISK06     ORCL:DISK06  CACHED  ONLINE  NORMAL
DISK07     ORCL:DISK07  CACHED  ONLINE  NORMAL
DISK08     ORCL:DISK08  CACHED  ONLINE  NORMAL

8 rows selected.

Each disk has its own failure group as its name.

Dropping and adding disks repeatedly, in this case, the failure groups are FG1, FG2, FG3 and FG4.
SQL> alter diskgroup data drop disk disk01, disk02 rebalance power 1 wait;

Diskgroup altered.

SQL> alter diskgroup data add failgroup fg1 disk 'ORCL:DISK01', 'ORCL:DISK02' rebalance power 1 wait;

Diskgroup altered.

SQL> alter diskgroup data drop disk disk03, disk04 rebalance power 1 wait;

Diskgroup altered.

SQL> alter diskgroup data add failgroup fg2 disk 'ORCL:DISK03', 'ORCL:DISK04' rebalance power 1 wait;

Diskgroup altered.

SQL> alter diskgroup data drop disk disk05, disk06 rebalance power 1 wait;

Diskgroup altered.

SQL> alter diskgroup data add failgroup fg3 disk 'ORCL:DISK05', 'ORCL:DISK06' rebalance power 1 wait;

Diskgroup altered.

SQL> alter diskgroup data drop disk disk07, disk08 rebalance power 1 wait;

Diskgroup altered.

SQL> alter diskgroup data add failgroup fg4 disk 'ORCL:DISK07', 'ORCL:DISK08' rebalance power 1 wait;

Diskgroup altered.

Let's check the result of rearrangement.
SQL> select dg.name diskgroup, dk.path, dk.name disk_name, dk.failgroup, dk.mount_status, dk.mode_status from v$asm_disk dk, v$asm_diskgroup dg where dk.group_number = dg.group_number;

DISKGROUP  PATH         DISK_NAME  FAILGROUP  MOUNT_S MODE_ST
---------- ------------ ---------- ---------- ------- -------
DATA       ORCL:DISK01  DISK01     FG1        CACHED  ONLINE
DATA       ORCL:DISK02  DISK02     FG1        CACHED  ONLINE
DATA       ORCL:DISK03  DISK03     FG2        CACHED  ONLINE
DATA       ORCL:DISK04  DISK04     FG2        CACHED  ONLINE
DATA       ORCL:DISK05  DISK05     FG3        CACHED  ONLINE
DATA       ORCL:DISK06  DISK06     FG3        CACHED  ONLINE
DATA       ORCL:DISK07  DISK07     FG4        CACHED  ONLINE
DATA       ORCL:DISK08  DISK08     FG4        CACHED  ONLINE

8 rows selected.

SQL> select name disk_name, path, mount_status, mode_status, state from v$asm_disk;

DISK_NAME  PATH         MOUNT_S MODE_ST STATE
---------- ------------ ------- ------- --------
DISK01     ORCL:DISK01  CACHED  ONLINE  NORMAL
DISK02     ORCL:DISK02  CACHED  ONLINE  NORMAL
DISK03     ORCL:DISK03  CACHED  ONLINE  NORMAL
DISK04     ORCL:DISK04  CACHED  ONLINE  NORMAL
DISK05     ORCL:DISK05  CACHED  ONLINE  NORMAL
DISK06     ORCL:DISK06  CACHED  ONLINE  NORMAL
DISK07     ORCL:DISK07  CACHED  ONLINE  NORMAL
DISK08     ORCL:DISK08  CACHED  ONLINE  NORMAL

8 rows selected.

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