When you want to delete an ASM diskgroup, you might encounter the following error:
ORA-15027: active use of diskgroup “DATA” precludes its dismount
Getting rid of ASM diskgroup
So, I was doing some tests with Oracle ASM, but somehow I could not remove my ASM disk group.
SQL> drop diskgroup data including contents; drop diskgroup data including contents * ERROR at line 1: ORA-15039: diskgroup not dropped ORA-15027: active use of diskgroup "DATA" precludes its dismount
Strange, I just created this, but I could not delete it. No database was using it!?
SQL> select * from v$asm_client; no rows selected
WARNING: ALL DATA WILL BE LOST! MAKE SURE YOU HAVE BACKUPS!
Luckally one is able to force this all…
SQL> alter diskgroup data dismount force; SQL> drop diskgroup data force including contents; Diskgroup dropped.