| ORA-15027: | active use of diskgroup "string" precludes its dismount |
| Cause: | An ALTER DISKGROUP ... DISMOUNT command specified a diskgroup which had database client instances with open files in the diskgroup. Diskgroups cannot be dismounted until all open files in the diskgroup are closed by the database client instances. |
| Action: | Stop all clients that are using this diskgroup and retry the ALTER DISKGROUP ... DISMOUNT command. The V$ASM_CLIENT fixed view in an ASM instance provides a list of its active database client instances.
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