Upgrade to 11g

upgrade to 11g
Paths
9.2.0.6->9.2.0.8->11.2.0.1
8.1.7.0->8.1.7.4->10.2.0.4->11.2.0.1
Upgrade ASM Instance
1.    groupadd asmadmin
2.    usermod -a -G asmadmin oracle
3.    set ASM Instance
4.    / as sysdba
create user username identified by password;
grant sysdba to username;
select * from v$pwfile_users;
5.    ASM is part of Grid Infrastructure from 11g R2 onwards
6.    ./runInstaller
7.    ./rootupgrade.sh
Upgrade Database Instance
1.    Install the Software
2.    Run Pre-Upgrade Information Tool
spool /tmp/upgrade.spl
@?/rdbms/admin/utlu112i.sql
spool off
3.dbua
Notes to keep in mind
1. there are no parameters in init.ora like background_dump_dest, core_dump_dest,user_dump_dest rather ther is one diagnostic_dest parameter
also _lgwr_async_io=true is also invalid
2.Listener log file format is XML to make it text
DIAG_ADR_ENABLED_LISTENER_SID=OFF
3.to speed up 11g upgrade performance create dictionary statistics
exec dbms_stats.gather_dictionary_stats;
purge recyclebin
purge dba_recyclebin;
try taking backup of aud$ if the data is not important in aud$
if important then update the statement mannually
and run catupgrd.sql