Resolving ORA-01033 "initialization or shutdown in progress" I followed the instructions at http://www.oracle-base.com/articles/10g/oracle-data-pump-10g.php to create a database export.  

I used:

expdp scott/tiger@db10g full=Y directory=TEST_DIR dumpfile=DB10G.dmp logfile=expdpDB10G.log


to create the export. However I get this error message:

UDE-00008: operation generated ORACLE error 12154
ORA-01033: ORACLE initialization or shutdown in progress


How do I resolve this issue?
First:

sqlplus /nolog 


Then:

connect / @bdlocal as sysdba 


(Alternatively, use sqlplus / as sysdba instead of the above two steps.)

Check the status (I guess it will tell you anything but STARTUP):

select status from v$instance; 


Then turn it completly off: 

shutdown immediate; 


Then start it:

startup;


If you get errors starting up, check the alert log and your favorite search engine (searching for the ORA-xxxx alert number is a good place to start). If you can't figure it out, you can ask a question about that here (including the relevant part of the alert log or any other errors you see).