DB2 Server Table Space Locked
First I'd say you want to know what tablespace it is. A lot of times I connect to the database and use LIST TABLESPACES SHOW DETAIL to figure out what is happening. Look at each tablespace and see what value is set for the "State" field on each. You want a "zero" value for the tablespace to be fine.

And here is a handy query:

select substr(tbsp_name,1,30) as tbsp_name, substr(TBSP_STATE,1,18) as TBSP_STATE 
from TABLE(MON_GET_TABLESPACE('',-2)) with ur


This gets all tablespaces with a human readable state. Found this off of Ember Crooks' blog, which I follow. Very useful.

Anyway first you want to know which space it is an what state it is in. Once you know that, you can either deal with it or dig further. For example, if the tablespace is quiesced, then you only need to unquiesce it or reset the quiesce. I'd still ask why....Perhaps you have an ETL job or something that quiesces the tablespace and doesn't release it properly if it fails? Or take a peek at your the diaglogs to see what was going on at the time (very key here).

Try those out and let us know what it going on.