About Oracle RAC 11g rebuilding the disk group

Delete and rebuild very quickly, old iron, it's an empty library anyway, stop the ink, go up a shuttle.

Delete it directly and then ASMCA

DROP DISKGROUP DATA INCLUDING CONTENTS;

Your data files, control files, and parameter files are all in the DATA disk group.
If you delete the disk group directly, your library will not be able to get up.But there are still some missing files on the server that might prevent you from rebuilding the library.Therefore, it is recommended to redo the system and start over, which is safer.

Reinstalling the system is too troublesome

normal means that the redundancy is 3, so the actual space usage is basically divided by 3. If you want to use 900G of space, you can use external redundancy to rebuild the disk group.

If you are worried about the command line risk, you can directly use the graphical delete, asmca goes in to delete the disk group, and then rebuilds directly in the graphical, select external redundancy.

Make an rman backup first, and then rebuild the disk group.