● oracle-xe.service - LSB: Oracle 11g Express Edition
   Loaded: loaded (/etc/init.d/oracle-xe)
   Active: failed (Result: exit-code) since lun 2015-08-24 22:24:32 CEST; 18min ago
     Docs: man:systemd-sysv-generator(8)
  Process: 12274 ExecStart=/etc/init.d/oracle-xe start (code=exited, status=1/FAILURE)

... systemd[1]: Starting LSB: Oracle 11g Express Edition...
... oracle-xe[12274]: Starting Oracle Net Listener.
... su[12282]: No passwd entry for user 'oracle'
... oracle-xe[12274]: Starting Oracle Database 11g Express Edition instance.
... su[12288]: No passwd entry for user 'oracle'
... oracle-xe[12274]: Failed to start Oracle Net Listener using /u01/app/oracle/product/11.2.0/xe/bin/tnslsnr and Oracle Express Database using /u01/app/oracle/product/11.2.0/xe/bin/sqlplus.
... systemd[1]: oracle-xe.service: control process exited, code=exited status=1
... systemd[1]: Failed to start LSB: Oracle 11g Express Edition.
... systemd[1]: Unit oracle-xe.service entered failed state.
... systemd[1]: oracle-xe.service failed.

...
.. polkitd(authority=local)[641]: Registered Authentication Agent for unix-process:12249:680724 (system bus name :1.73 [/usr/bin/pkttyagent --notify-fd 5 --fallback], object path /org/freedesktop/PolicyKit1/AuthenticationAgent, locale es_ES.UTF-8)
... systemd[1]: Starting LSB: Oracle 11g Express Edition...
-- Subject: Unit oracle-xe.service has begun start-up
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit oracle-xe.service has begun starting up.
... oracle-xe[12274]: Starting Oracle Net Listener.
... su[12282]: No passwd entry for user 'oracle'
... su[12282]: FAILED su for oracle by root
... su[12282]: - ??? root:oracle
... oracle-xe[12274]: Starting Oracle Database 11g Express Edition instance.
... su[12288]: No passwd entry for user 'oracle'
... su[12288]: FAILED su for oracle by root
... su[12288]: - ??? root:oracle
... oracle-xe[12274]: Failed to start Oracle Net Listener using /u01/app/oracle/product/11.2.0/xe/bin/tnslsnr and Oracle Express Database using /u01/app/oracle/product/11.2.0/xe/bin/sqlplus.
... systemd[1]: oracle-xe.service: control process exited, code=exited status=1
... systemd[1]: Failed to start LSB: Oracle 11g Express Edition.
-- Subject: Unit oracle-xe.service has failed
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit oracle-xe.service has failed.
--
-- The result is failed.
... systemd[1]: Unit oracle-xe.service entered failed state.
... systemd[1]: oracle-xe.service failed.
... polkitd(authority=local)[641]: Unregistered Authentication Agent for unix-process:12249:680724 (system bus name :1.73, object path /org/freedesktop/PolicyKit1/AuthenticationAgent, locale es_ES.UTF-8) (disconnected from bus)
... sudo[12248]: pam_unix(sudo:session): session closed for user root
... pkexec[12404]: pam_unix(polkit-1:session): session opened for user root by (uid=1000)
... pkexec[12404]: jose: Executing command [USER=root] [TTY=unknown] [CWD=/home/jose] [COMMAND=/usr/lib/update-notifier/package-system-locked]
... kernel: toshiba_acpi: Unknown key 120

unzip oracle-xe-11.2.0-1.0.x86_64.rpm.zip

unzip oracle-xe-11.2.0-1.0.x86_64.rpm.zip

sudo apt-get install alien libaio1 unixodbc vim

sudo vim /sbin/chkconfig

#!/bin/bash
# Oracle 11gR2 XE installer chkconfig hack for Ubuntu
file=/etc/init.d/oracle-xe
if [[ ! `tail -n1 $file | grep INIT` ]]; then
echo >> $file
echo '### BEGIN INIT INFO' >> $file
echo '# Provides: OracleXE' >> $file
echo '# Required-Start: $remote_fs $syslog' >> $file
echo '# Required-Stop: $remote_fs $syslog' >> $file
echo '# Default-Start: 2 3 4 5' >> $file
echo '# Default-Stop: 0 1 6' >> $file
echo '# Short-Description: Oracle 11g Express Edition' >> $file
echo '### END INIT INFO' >> $file
fi
update-rc.d oracle-xe defaults 80 01

chmod 755 /sbin/chkconfig

sudo vim /etc/sysctl.d/60-oracle.conf

# Oracle 11g XE kernel parameters
fs.file-max=6815744
net.ipv4.ip_local_port_range=9000 65000
kernel.sem=250 32000 100 128
kernel.shmmax=536870912
(Save the file)
Note: kernel.shmmax = max possible value , e.g. size of physical RAM ( in bytes e.g. 512MB RAM == 512*1024*1024 == 536870912 bytes )
Verify the change :
sudo cat /etc/sysctl.d/60-oracle.conf

sudo service procps start

free -m

i) `ln -s /usr/bin/awk /bin/awk`

ii) `mkdir /var/lock/subsys`

iii) `touch /var/lock/subsys/listener`

A valid HTTP port for the Oracle Application Express (the default is 8080)
A valid port for the Oracle database listener (the default is 1521)
A password for the SYS and SYSTEM administrative user accounts
Confirm password for SYS and SYSTEM administrative user accounts
Whether you want the database to start automatically when the computer starts (next reboot).

export ORACLE_HOME=/u01/app/oracle/product/11.2.0/xe
export ORACLE_SID=XE
export NLS_LANG=`$ORACLE_HOME/bin/nls_lang.sh`
export ORACLE_BASE=/u01/app/oracle
export LD_LIBRARY_PATH=$ORACLE_HOME/lib:$LD_LIBRARY_PATH
export PATH=$ORACLE_HOME/bin:$PATH

. ./.profile

sudo service oracle-xe start

The output should be similar to following :
user@machine:~$ sudo service oracle-xe start
Starting Oracle Net Listener.
Starting Oracle Database 11g Express Edition instance.
user@machine:~$

sqlplus sys as sysdba

SQL*Plus: Release 11.2.0.2.0 Production on Wed May 9 12:12:16 2012

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

Enter password:

Connected to:
Oracle Database 11g Express Edition Release 11.2.0.2.0 - 64bit Production

SQL>

SQL> create user username identified by password;

User created.

SQL> grant connect,resource to username;

Grant succeeded.

user@machine:~$ sqlplus

SQL*Plus: Release 11.2.0.2.0 Production on Wed May 9 12:28:48 2012

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

Enter user-name: temp
Enter password:

Connected to:
Oracle Database 11g Express Edition Release 11.2.0.2.0 - 64bit Production

SQL> select 2+2 from dual;
2+2
----------
4
SQL>