文档解释
ORA-15027: active use of diskgroup “string” precludes its dismount
Cause: An ALTER DISKGROUP … DISMOUNT command specified a diskgroup which had clients with open files in the diskgroup. Diskgroups cannot be dismounted until all open files in the diskgroup are closed.
Action: Stop all clients that are using this diskgroup and retry the ALTER DISKGROUP … DISMOUNT command. Query the V$ASM_CLIENT fixed view in an ASM instance or use ASMCMD LSOF to list active clients.
ORA-15027：当试图卸载某个存储组（Diskgroup）时引发的错误，ORA-15027的官方解释是：active use of diskgroup “string” precludes its dismount，提示存储组正在使用中，无法卸载。
常见案例
正常处理方法及步骤
1.首先，可以尝试更改状态将存储组挂起以释放存储组。
SQL> ALTER DISKGROUP MOUNT;
SQL> ALTER DISKGROUP DISMOUNT;
2.如果挂起失败，则可以尝试使用ALTER DISKGROUP ONLINE/OFFLINE命令来解除该存储组对应的实例。
SQL> ALTER DISKGROUP OFFLINE INSTANCE;
3.最后，在这些步骤之后，应该可以成功地使用EXPORT等命令来卸载 Diskgroup。
SQL> EXPORT DISKGROUP CONTENTS=ALL;
