Dropping a Disk Group

To drop a disk group, the ASM instance has to be up and running, the disk group has to be mounted, and no files in the disk group should be open. The DROP DISKGROUP command does not return until the action is completed. This command will remove the disk group name from the asm_diskgroups parameter when the server parameter file is used. With init.ora files, the diskgroup has to be manually removed from the asm_diskgroups parameter after the DROP operation and before the next shutdown of the ASM instance.

To drop dskgrp01 with its contents, use the following command:

DROP DISKGROUP dskgrp01 INCLUDING CONTENTS

Internal Consistency of Disk Groups

After doing any of these operations to disk groups, the DBA may want to verify the internal consistency of the disk group metadata.  For this purpose use the ALTER DISKGROUP …. CHECK command. Specific files can be checked, some disks or all disks in a disk group can be checked, or specific failure groups in a disk group can be checked. The disc group has to be in the mounted state for these checks to occur.

ASM will attempt to correct any errors during this operation. If there are any errors, it will be displayed and written to an alert log. Unless the user specifies a NOREPAIR clause, ASM will fix any error situation.

To check the consistency in the metadata for all disks in the dskgrp01 disk group, use the following command: