Stop ASM instance in standalone database

Stop asm instance in standalone database 

If you need to close ASM than you need to also close database

You need to close db:

srvctl stop database -d instance_name
or
set ORACLE_HOME and ORACLE_SID

sqlplus "/as sysdba"
shutdown immediate;

srvctl stop LISTENER
srvctl stop ASM -f


# to stop an ASM instance, please use the below command:
srvctl stop asm [-o stop_options] [-f]

-o stop_options

     Options for the shutdown operation, for example, NORMAL, TRANSACTIONAL, IMMEDIATE, or ABORT

-f

     Force. Must be present if disk groups are currently started (mounted). This option enables SRVCTL to stop the disk groups before stopping Oracle ASM. Each dependent database instance is also stopped according to its stop options, or with the ABORT option if the configured stop options fail.