sqlplus not connecting to Oracle XE 11g I installed Oracle XE 11g on my Ubuntu in vmware fusion. The oracle installation is all went fine but I am not able to connect the oracle database using sqlplus. I am getting this exception:  

$ sqlplus

SQL*Plus: Release 11.2.0.2.0 Production on Wed May 27 18:40:24 2015

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

Enter user-name: system
Enter password: 
ERROR:
ORA-01034: ORACLE not available
ORA-27102: out of memory
Linux-x86_64 Error: 12: Cannot allocate memory
Additional information: 1
Additional information: 3309588
Additional information: 8
Process ID: 0
Session ID: 0 Serial number: 0


I followed the instructions as per this excellent blog http://blog.whitehorses.nl/2014/03/18/installing-java-oracle-11g-r2-express-edition-and-sql-developer-on-ubuntu-64-bit/ and got everything installed but feels like I am missing something obvious. 
My have setup Vmware fusion with 2GB of Memory.
Cannot allocate memory means you have not enough ram.
check the memory requirements  in the oralce guide