I installed Hadoop2.2.0 and Hbase0.98.0 and here is what I do :
$ ./bin/start-hbase.sh $ ./bin/hbase shell 2.0.0-p353 :001 > list
the
This could also happen if the vm or the host machine is put to sleep ,Zookeeper will not stay live. Restarting the VM should solve the problem.