SAXParseException hadoop-2.7.2

Caused by: org.xml.sax.SAXParseException; systemId: file:/usr/local/hadoop-2.7.2/etc/hadoop/core-site.xml; lineNumber: 1; columnNumber: 1; Content is not allowed in prolog

solution :

check xml configuration of the file.
cause due not proper closing of tag

hadoop-env.sh missing in hadoop 2.7

hadoop-env.sh missing in hadoop 2.7

earlier location :

/conf/hadoop-env.sh

location is changed to

/etc/hadoop/hadoop-env.sh