Firstly verify the table space is regular table space and it has reached its limit 512GB.
You can check this by running “db2pd -tab -db <yourdb>” or connecting to database then run db2 list tablespaces show detail.
Once it is confirmed that the table space size limit has been reached(512GB), convert the table space to large.
Converting a regular DB2 DMS tablespace to LARGE
In addition, check the following notes.
1) Converting the tablepace from regular to large will lift the tablespace limit from 512G to 64T.
2) after conversion, any new table/indexes will be able to use large RIDs, and their table/index limit also lifted from 512G to 64T (table size limit is the same as tablespace limit)
3) for existing tables/indexes, without reorg indexes or reorg tables,
they can continue to grow as the table space limit has been lifted but
will use old 4bytes RID so the table/index itself will remain the original size limit of 512G.
4) for existing tables, after offline table reorg (which will reorg
indexes as well), each table will be able to lift the size limit from 512G to 64T.
You can also refer to the following