Just started with cassandra 

1. Unpacked apache-cassandra-2.0.1
2. Created /var/lib/cassandra/ & /var/log/cassandra//
3. Modified the owner from root to deepakkv
4. deepakkv@ubuntu:~/ebay/softwares/apache-cassandra-2.0.1$ java -version
java version "1.6.0_45"
Java(TM) SE Runtime Environment (build 1.6.0_45-b06)
Java HotSpot(TM) 64-Bit Server VM (build 20.45-b01, mixed mode)
5. Ubuntu
Linux ubuntu 3.2.0-29-generic #46-Ubuntu SMP Fri Jul 27 17:03:23 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux
6. bin/cassandra -f 

xss =  -ea -javaagent:bin/../lib/jamm-0.2.5.jar -XX:+UseThreadPriorities -XX:ThreadPriorityPolicy=42 -Xms2932M -Xmx2932M -Xmn600M -XX:+HeapDumpOnOutOfMemoryError -Xss256k
Exception in thread "main" java.lang.UnsupportedClassVersionError: org/apache/cassandra/service/CassandraDaemon : Unsupported major.minor version 51.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631)
at java.lang.ClassLoader.defineClass(ClassLoader.java:615)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
Could not find the main class: org.apache.cassandra.service.CassandraDaemon.  Program will exit.


How to fix it ?

--
Deepak