...no puedo bajar ASM

Hoy estaba tratando de bajar las instancia ASM standalone y me surgio el siguiente error ORA-15487, era que habia montado una particion ACFS...

[grid@test(+ASM) ~]->. oraenv
[grid@test(+ASM) ~]->sqlplus / as sysasm
 SQL> SHUTDOWN NORMAL


ERROR al bajar ASM

SQL> shutdown normal
ORA-15487: cannot shutdown the ASM instance with an open ASM volume
SQL> exit


[oracle@test(11g) trace]-> ps aux | grep grid | grep LOCAL

 3772 ?        Ss     0:00 oracle+ASM (DESCRIPTION=(LOCAL=YES)(ADDRESS=(PROTOCOL=beq)))
 3916 pts/1    S+     0:00 grep LOCAL
23146 ?        Ss     0:04 oracle+ASM (DESCRIPTION=(LOCAL=YES)(ADDRESS=(PROTOCOL=beq)))

[oracle@test(11g) trace]->kill -15 3772 23146



[root@test~]# mount
/dev/cciss/c1c1 on / type ext3 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
tmpfs on /dev/shm type tmpfs (rw)
/dev/cciss/c0d0p6 on /opt type ext3 (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)
oracleasmfs on /dev/oracleasm type oracleasmfs (rw)
/dev/asm/testos-221 on /opt/acfsmounts/dat type acfs (rw)

[root@test~]# umount /opt/acfsmounts/dat
[root@test~]# mount


[grid@test(+ASM) ~]->sqlplus / as sysasm

SQL*Plus: Release 11.2.0.3.0 Production on Tue Jul 30 11:54:55 2013

Copyright (c) 1982, 2011, Oracle.  All rights reserved.


Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
With the Automatic Storage Management option

SQL> shutdown normal
ASM diskgroups volume disabled
ASM diskgroups dismounted
ASM instance shutdown
SQL>