Can't change /etc/oratab file or automatic startup problem on linux!!!

Question

Hi friends,
I have installed an Oracle 11.2.0.1 on Oracle Linux Server 5.11(Virtualbox). I have the users grid and oracle11g. Add groups and install grid infrastructure first as a grid user and install database as oracle user as in documentation successfully.
I have following users and groups as
[grid@orcl11g ~]$ id grid
   uid=501(grid) gid=502(oinstall) groups=502(oinstall),492(vboxsf),501(grid),503(dba),505(asmdba),506(asmadmin),507(asmoper)
[grid@orcl11g ~]$ id oracle11g
   uid=500(oracle11g) gid=502(oinstall) groups=502(oinstall),500(oracle11g),492(vboxsf),503(dba),504(oper),505(asmdba)
When I log on as grid user. I check the followings:
[grid@orcl11g ~]$ crsctl check has
CRS-4638: Oracle High Availability Services is online
[grid@orcl11g ~]$ srvctl status database -d ora11g
Database is running.
[grid@orcl11g ~]$ sqlplus sys as sysdba
SQL*Plus: Release 11.2.0.1.0 Production on Thu Dec 25 19:17:37 2014
Copyright (c) 1982, 2009, Oracle.  All rights reserved.
Enter password:
Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production
With the Automatic Storage Management option
SQL> select status from v$instance;
STATUS
STARTED
When I log as  oracle user. I check the followings:
[oracle11g@orcl11g ~]$ sqlplus sys as sysdba
SQL*Plus: Release 11.2.0.1.0 Production on Thu Dec 25 19:21:46 2014
Copyright (c) 1982, 2009, Oracle.  All rights reserved.
Enter password:
Connected to an idle instance.
SQL> select status from v$instance;
STATUS
OPEN
Till here everything is OK!!!!
When I edit /etc/oratab file; change N to Y for +ASM and restart the system, then it seems value N is not changed to Y. But changed for database as shown below.
     +ASM:/u01/app/grid/product/11.2.0/grid:N   # line added by Agent
     ora11g:/u01/app/oracle/product/11.2.0/dbhome_1:Y
QUESTIONS!!!!!
1. When I edit /etc/oratab file manually why second row saved (changed N to Y manually) but the first row become unsaved (although changed N to Y) again after restarting the system?
2. After restarting the system database and ASM started automatically, although the line is not changed to Y above (in oratab file) for ASM. What is the reason and how can I change to Y? Or if I have to change the N to Y or not?
3. Is it enough to edit N to Y in oratab file for ASM and database to start ASM and database automatically? I think there will be some other scripts have to be created in /etc/init.d/ directory for automatic startup.
PLEASE HELP ME TO UNDERSTAND THIS PROBLEM CLEARLY!!!!
Thanks!!!
Message was edited by: DBA_84

Answer 1

Thanks for reply ZeDBA,
I don't want to prevent auto starting. As 2769577 stated above that
    "...You may not need to edit in oratab since it's automatically taken care by HAS in 11g..."
It is meaningful and perhaps it is the exact reason or solution.
Question is that, why I can't edit oratab file manually for ASM row? ' Not need ' and ' can't ' is different!!
# The first and second fields are the system identifier and home
# directory of the database respectively.  The third filed indicates
# to the dbstart utility that the database should , "Y", or should not,
# "N", be brought up at system boot time.
# Multiple entries with the same $ORACLE_SID are not allowed.
+ASM:/u01/app/grid/product/11.2.0/grhome_1:N        # line added by Agent
ora11g:/u01/app/oracle11g/product/11.2.0/dbhome_1:Y
If we assume the 2769577's answer is exactly correct, reason or solution. Then it means that the row "..
+ASM:/u01/app/grid/product/11.2.0/grhome_1:N  
# line added by Agent
in oratab file is meaningless and unnecessary if HAS process enabled and automatically start the ASM.
Please clarify it, If I am wrong?
Thanks!!!