Not able to deploy ROOT.war in tomcat 7

I have purchased DigitalOcean server and I am trying to run a java application. I am using ubuntu OS and tomcat 7 server where my webapps folder is located in :

     /usr/share/tomcat7

Now, I have scp my ROOT.war in the folder and restarted tomcat server and apache. But my application is not running. In the file catalina.2014-02-09.log, it shows:

          java.io.IOException: Unable to create the directory [/usr/share/tomcat7/webapps/ROOT/META-INF]
    at org.apache.catalina.startup.ExpandWar.expand(ExpandWar.java:132)
    at org.apache.catalina.startup.ContextConfig.fixDocBase(ContextConfig.java:697)
    at org.apache.catalina.startup.ContextConfig.init(ContextConfig.java:820)
    at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:363)
    at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)
    at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90)
    at org.apache.catalina.util.LifecycleBase.setStateInternal(LifecycleBase.java:401)
    at org.apache.catalina.util.LifecycleBase.init(LifecycleBase.java:110)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:139)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:89

One more error I see in the same log is :

         java.lang.IllegalStateException
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1587)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1546)
    at org.hibernate.dialect.MySQLDialect$1.convert(MySQLDialect.java:404) at          org.hibernate.exception.internal.StandardSQLExceptionConverter.conver

I am not able to understand what can be the cause of this issue? As per http://stackoverflow.com/questions/15113700/how-to-make-tomcat-explode-the-war-files , I have configured server.xml for unpack war as

      <Host name="localhost"  appBase="/usr/share/tomcat7/webapps"
        unpackWARs="true" autoDeploy="true">

But still no results. Please help me out here. Any suggestions can be helpful.