How to resize disk capacity while replacing disk in asm diskgroup

SYMPTOMS

The new disk and old disk do not have equal size.

ORA-15410: Disks in disk group OCRDG do not have equal size.

SOLUTION

Determine the capacity of the new disk and the old disk.

SQL> select name,os_mb,total_mb,free_mb,hot_used_mb,cold_used_mb,sector_size from v$asm_disk;

• new disk less than old disk.

SQL> alter diskgroup ocrdg resize disk OCRDG_0000 size 5119M, OCRDG_0001 size 5119M, OCRDG_0002 size 5119M;
SQL> alter diskgroup ocrdg add disk '/dev/oracleasm/disks/NEW_ASM_OCR1','/dev/oracleasm/disks/NEW_ASM_OCR2','/dev/oracleasm/disks/NEW_ASM_OCR3';
SQL> alter diskgroup ocrdg drop disk OCRDG_0000,OCRDG_0001,OCRDG_0002;

• new disk great than old disk.

SQL> alter diskgroup ocrdg add disk '/dev/oracleasm/disks/NEW_ASM_OCR1' size 5119M, '/dev/oracleasm/disks/NEW_ASM_OCR2' size 5119M, '/dev/oracleasm/disks/NEW_ASM_OCR3' size 5119M;
SQL> alter diskgroup ocrdg drop disk OCRDG_0000,OCRDG_0001,OCRDG_0002;
SQL> alter diskgroup ocrdg resize disk NEW_ASM_OCR1 size 5236M, NEW_ASM_OCR2 size 5236M, NEW_ASM_OCR3 size 5236M;