Numerous times users have come with issues setting up HBase on Ubuntu because it has the 127.0.1.1 line messing everything. Here's an example:
2011-12-10 00:18:24,312 INFO org.apache.hadoop.hbase.regionserver.HRegionServer: Serving as localhost,33371,1323476299775, RPC listening on /127.0.1.1:33371, sessionid=0x1342555adc90002
2011-12-10 00:18:27,135 DEBUG org.apache.hadoop.hbase.master.AssignmentManager: Assigning region
ROOT,,0.70236052 to localhost,33371,1323476299775
2011-12-10 00:18:27,135 DEBUG org.apache.hadoop.hbase.master.ServerManager: New connection to localhost,33371,1323476299775
2011-12-10 00:18:27,155 INFO org.apache.hadoop.ipc.HbaseRPC: Server at /127.0.0.1:33371 could not be reached after 1 tries, giving up.
2011-12-10 00:18:27,156 WARN org.apache.hadoop.hbase.master.AssignmentManager: Failed assignment of
ROOT,,0.70236052 to serverName=localhost,33371,1323476299775, load=(requests=0, regions=0, usedHeap=23, maxHeap=983), trying to assign elsewhere instead; retry=0
org.apache.hadoop.hbase.client.RetriesExhaustedException: Failed setting up proxy interface org.apache.hadoop.hbase.ipc.HRegionInterface to /127.0.0.1:33371 after attempts=1
We should have a special check in standalone mode to make sure we won't fall into that trap and then print a useful error message that would hopefully appear on the command line.