If any command is not working in hbase please follow below steps to restart Hbase shell
1) cd /usr/lib/hbase-0.96.2-hadoop2/
2) sudo rm -r hbasestorage/*
3) sudo rm -r logs/*
4) ./bin/start-hbase.sh
5) hbase shell
you can also execute below command to alter table schema
1. Creating table MyTable with column family cf1
create 'MyTable', 'cf'
2. Adding recoreds in MyTable
put 'MyTable','row1','cf:name','abhishek'
put 'MyTable','row1','cf:name','andy'
put 'MyTable','row2','cf:name','Ajay'
3. Disable table to make changes in table schema
disable 'MyTable'
4. Alter table, here we are adding one more column family naming cf2
alter 'MyTable', {NAME => 'cf2'}
5. Enable table
enable 'MyTable'
6. Adding recoreds in column family cf2 in MyTable
put 'MyTable','row3','cf2:name','Ajay'
7. Now do scan in MyTable and you can see the changes
scan 'MyTable'
Now by executing above steps will change my table, you can refer below screen shot for your reference
