hadoop.tmp.dir /opt/hadoop/tmp A base for other temporary directories. dfs.data.dir /opt/hadoop/${user.name} Comma separated list of paths on the local filesystem of a DataNode where it should store its blocks. dfs.default.name hdfs://aldenv136allegheny.edu:54310 The name of the default file system. A URI whose scheme and authority determine the FileSystem implementation. The uri's scheme determines the config property (fs.SCHEME.impl) naming the FileSystem implementation class. The uri's authority is used to determine the host, port, etc. for a filesystem. dfs.replication 3 Default block replication. The actual number of replications can be specified when the file is created. The default is used if replication is not specified in create time.