Case: (All Disks in a failgroup are lost after a disk/LUN failure)

Suppose All Disk (VOL4, VOL5) in failgroup (Controller2) is lost.

Workaround:

• Execute following query on ASM instance. (This will show you ASM disk status)

Select GROUP_NUMBER, DISK_NUMBER, MOUNT_STATUS, STATE, REDUNDANCY, TOTAL_MB, FREE_MB, FAILGROUP, NAME from v$asm_disk;

GROUP            DISK         MOUNT_S          STATE      REDUNDA     TOTAL_MB FREE_MB   FAILGROUP       NAME

1                     3              MISSING            NORMAL    UNKNOWN  0                0                                        VOL4

1                    4               MISSING            NORMAL    UNKNOWN  0                0                                        VOL5

1                    0              CACHED             NORMAL     UNKNOWN 2047           1269      CONTROLLER1     VOL1

Result will show Disk VOL4 and VOL5 is Missing.

• Add Disk physically, create partition, and scan ASM disk and list ASM disk. You will show delete disk (VOL4 and VOL5)

• Again execute bellow Query:

Select GROUP_NUMBER, DISK_NUMBER, MOUNT_STATUS, STATE, REDUNDANCY, TOTAL_MB, FREE_MB, FAILGROUP, NAME from v$asm_disk;

GROUP DISK      MOUNT_S             STATE          REDUNDA           TOTAL_MB       FREE_MB           FAILGROUP      NAME

0           0          CLOSED                NORMAL       UNKNOWN          2047                0

0           1          CLOSED                NORMAL       UNKNOWN          3067                0

1           4          MISSING                HUNG          UNKNOWN           0                     0                                               VOL5

1           3          MISSING                HUNG          UNKNOWN           0                     0                                               VOL4

1            0         CACHED                 NORMAL      UNKNOWN          2047                1269                CONTROLLER1  VOL1

• Now delete the ASM Disk, scan ASM Disk and list disk (VOL4 and VOL5)

/etc/init.d/oracleasm deletedisk VOL4

/etc/init.d/oracleasm deletedisk VOL5

The list ASM disk will not show Disk (VOL4 and VOL5)

• Create ASM Disk, scan and list ASM Disk with Different Disk name.

/etc/init.d/oracleasm createdisk VOL 4NEW /dev/sdc1

/etc/init.d/oracleasm createdisk VOL 5NEW /dev/sdd1

The list ASM Disk will show Disk (VOL4NEW and VOL5NEW)

• Now we add Newelly added ASM Disk to DISKGROUP.

ALTER DISKGROUP ADD FAILGROUP
DISK 'ORCL: VOL4NEW’,’ORCL: VOL5NEW’;

• Execute following query and check your disk status.

Select GROUP_NUMBER, DISK_NUMBER, MOUNT_STATUS, STATE, REDUNDANCY, TOTAL_MB, FREE_MB, FAILGROUP, NAME from v$asm_disk;

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Case: (One or two Disk but not all Disks in a failgroup are lost after a disk/LUN failure)

Suppose One Disk (VOL5) in failgroup (Controller2) is lost.

Workaround:

• Execute following query on ASM instance. (This will show you ASM disk status)

Select GROUP_NUMBER, DISK_NUMBER, MOUNT_STATUS, STATE, REDUNDANCY, TOTAL_MB, FREE_MB, FAILGROUP, NAME from v$asm_disk;

GROUP    DISK      MOUNT_S     STATE      REDUNDA      TOTAL_MB     FREE_MB     FAILGROUP       NAME

1              2          MISSING       NORMAL   UNKNOWN    0                   0                                          VOL5

1             0           CACHED       NORMAL    UNKNOWN    2047            1269            CONTROLLER1 VOL1

1             1           CACHED       NORMAL    UNKNOWN    2047            1732            CONTROLLER2 VOL4

Result will show Disk VOL5 is Missing.

• Add Disk physically, create partition, and scan ASM disk and list ASM disk. You will show delete disk (VOL5)

• Again execute bellow Query:

Select GROUP_NUMBER, DISK_NUMBER, MOUNT_STATUS, STATE, REDUNDANCY, TOTAL_MB, FREE_MB, FAILGROUP, NAME from v$asm_disk;

GROUP    DISK       MOUNT_S          STATE          REDUNDA      TOTAL_MB    FREE_MB     FAILGROUP       NAME

0             0            CLOSED             NORMAL       UNKNOWN     3067              0

1             0            CACHED             NORMAL       UNKNOWN     2047              1269         CONTROLLER1 VOL1

1             1            CACHED             NORMAL       UNKNOWN      2047              1269        CONTROLLER2 VOL4NEW

• Now delete the ASM Disk, scan ASM Disk and list disk (VOL5)

/etc/init.d/oracleasm deletedisk VOL5

The list ASM disk will not show Disk (VOL5)

• Create ASM Disk, scan and list ASM Disk with Different Disk name.

/etc/init.d/oracleasm createdisk VOL5 /dev/sdd1

The list ASM Disk will show Disk (VOL5)

• Now we add Newelly added ASM Disk to DISKGROUP.

ALTER DISKGROUP ADD FAILGROUP
DISK 'ORCL: VOL5’;

• Execute following query and check your disk status.

Select GROUP_NUMBER, DISK_NUMBER, MOUNT_STATUS, STATE, REDUNDANCY, TOTAL_MB, FREE_MB, FAILGROUP, NAME from v$asm_disk;

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